diff --git a/.pyup.yml b/.pyup.yml
index 3f9fa6a..18645ca 100644
--- a/.pyup.yml
+++ b/.pyup.yml
@@ -1,2 +1,2 @@
-branch: dev
+branch: master
 update: insecure
diff --git a/apybiomart/apybiomart.py b/apybiomart/apybiomart.py
index c791ae3..0b20f6f 100644
--- a/apybiomart/apybiomart.py
+++ b/apybiomart/apybiomart.py
@@ -7,65 +7,79 @@
     FiltersServer, Query
 
 
-def find_marts() -> pd.DataFrame:
-    """Retrieve and list available marts."""
-    server = MartServer()
+def find_marts(save: bool = False) -> pd.DataFrame:
+    """Retrieve and list available marts.
+
+    Args:
+        save: save results to a CSV file [default: False]
+    """
+    server = MartServer(save=save)
     return server.find_marts()
 
 
-def find_datasets(mart: str = "ENSEMBL_MART_ENSEMBL") -> pd.DataFrame:
+def find_datasets(mart: str = "ENSEMBL_MART_ENSEMBL",
+                  save: bool = False) -> pd.DataFrame:
     """Retrieve and list available datasets for a given mart.
 
     Args:
         mart: BioMart mart name (default: "ENSEMBL_MART_ENSEMBL")
+        save: save results to a CSV file [default: False]
     """
-    server = DatasetServer(mart)
+    server = DatasetServer(mart, save=save)
     return server.find_datasets()
 
 
-def find_attributes(dataset: str = "hsapiens_gene_ensembl") -> pd.DataFrame:
+def find_attributes(dataset: str = "hsapiens_gene_ensembl",
+                    save: bool = False) -> pd.DataFrame:
     """Retrieve and list available attributes for a given mart.
 
     Args:
         dataset: BioMart dataset name (default: "hsapiens_gene_ensembl")
+        save: save results to a CSV file [default: False]
     """
-    server = AttributesServer(dataset)
+    server = AttributesServer(dataset, save=save)
     return server.find_attributes()
 
 
-def find_filters(dataset: str = "hsapiens_gene_ensembl") -> pd.DataFrame:
+def find_filters(dataset: str = "hsapiens_gene_ensembl",
+                 save: bool = False) -> pd.DataFrame:
     """Retrieve and list available filters for a given mart.
 
     Args:
         dataset: BioMart dataset name (default: "hsapiens_gene_ensembl")
+        save: save results to a CSV file [default: False]
     """
-    server = FiltersServer(dataset)
+    server = FiltersServer(dataset, save=save)
     return server.find_filters()
 
 
 def query(attributes: List[str],
           filters: Dict[str, Union[str, int, list, tuple, bool]],
-          dataset: str = "hsapiens_gene_ensembl") -> pd.DataFrame:
+          dataset: str = "hsapiens_gene_ensembl",
+          save: bool = False) -> pd.DataFrame:
     """Launch synchronous query using the given attributes, filters and dataset.
 
     Args:
         attributes: list of attributes to include
         filters: dict of filter name : value to filter results
         dataset: BioMart dataset name (default: "hsapiens_gene_ensembl")
+        save: save results to a CSV file [default: False]
     """
-    server = Query(attributes, filters, dataset)
+    server = Query(attributes, filters, dataset, save=save)
     return server.query()
 
 
 async def aquery(attributes: List[str],
                  filters: Dict[str, Union[str, int, list, tuple, bool]],
-                 dataset: str = "hsapiens_gene_ensembl") -> pd.DataFrame:
+                 dataset: str = "hsapiens_gene_ensembl",
+                 save: bool = False) -> pd.DataFrame:
     """Launch asynchronous query using the given attributes, filters and dataset.
 
     Args:
         attributes: list of attributes to include
         filters: dict of filter name : value to filter results
         dataset: BioMart dataset name (default: "hsapiens_gene_ensembl")
+        save: save results to a CSV file [default: False]
     """
-    server = Query(attributes, filters, dataset)
+    server = Query(attributes, filters, dataset, save=save)
     return await server.aquery()
diff --git a/apybiomart/classes.py b/apybiomart/classes.py
index 74e0174..8f0af57 100644
--- a/apybiomart/classes.py
+++ b/apybiomart/classes.py
@@ -1,13 +1,14 @@
 #!/usr/bin/env python
 # -*- coding: UTF-8 -*-
 # Created by Roberto Preste
+import io
+from typing import Optional, Dict, Any, Tuple, Generator, List, Union
+from xml.etree import ElementTree as ET
+
 import asyncio
 import aiohttp
-import io
 import requests
 import pandas as pd
-from xml.etree import ElementTree as ET
-from typing import Optional, Dict, Any, Tuple, Generator, List, Union
 
 
 class _BiomartException(Exception):
@@ -20,11 +21,14 @@ class _Server:
 
     Attributes:
         host: URL to connect to
+        save: save results to a CSV file [default: False]
     """
 
     def __init__(self,
-                 host: str = "http://www.ensembl.org/biomart/martservice"):
+                 host: str = "http://www.ensembl.org/biomart/martservice",
+                 save: bool = False):
         self.host = host
+        self.save = save
         if not self._check_connection():
             raise _BiomartException("No internet connection available!")
 
@@ -76,8 +80,8 @@ async def get_async(self,
 class MartServer(_Server):
     """Class used to retrieve and list available marts."""
 
-    def __init__(self):
-        super().__init__()
+    def __init__(self, save: bool = False):
+        super().__init__(save=save)
 
     def find_marts(self) -> pd.DataFrame:
         """Return the list of available marts as a dataframe.
@@ -88,6 +92,9 @@ def find_marts(self) -> pd.DataFrame:
         df = pd.DataFrame.from_records(self._fetch_marts(),
                                        columns=["name", "display_name"])
         df.columns = ["Mart_ID", "Mart_name"]
+        df.replace(pd.np.nan, "", inplace=True)
+        if self.save:
+            df.to_csv("apybiomart_marts.csv", index=False)
 
         return df
 
@@ -131,8 +138,8 @@ class DatasetServer(_Server):
         mart: BioMart mart name
     """
 
-    def __init__(self, mart: str):
-        super().__init__()
+    def __init__(self, mart: str, save: bool = False):
+        super().__init__(save=save)
         self.mart = mart
 
     def find_datasets(self) -> pd.DataFrame:
@@ -147,6 +154,9 @@ def find_datasets(self) -> pd.DataFrame:
                          usecols=["name", "display_name"])
         df["mart"] = self.mart
         df.columns = ["Dataset_ID", "Dataset_name", "Mart_ID"]
+        df.replace(pd.np.nan, "", inplace=True)
+        if self.save:
+            df.to_csv("apybiomart_datasets.csv", index=False)
 
         return df
 
@@ -172,8 +182,8 @@ class AttributesServer(_Server):
         dataset: BioMart dataset name
     """
 
-    def __init__(self, dataset: str):
-        super().__init__()
+    def __init__(self, dataset: str, save: bool = False):
+        super().__init__(save=save)
         self.dataset = dataset
 
     def find_attributes(self) -> pd.DataFrame:
@@ -186,6 +196,9 @@ def find_attributes(self) -> pd.DataFrame:
         df["dataset"] = self.dataset
         df.columns = ["Attribute_ID", "Attribute_name",
                       "Attribute_description", "Dataset_ID"]
+        df.replace(pd.np.nan, "", inplace=True)
+        if self.save:
+            df.to_csv("apybiomart_attributes.csv", index=False)
 
         return df
 
@@ -236,8 +249,8 @@ class FiltersServer(_Server):
         dataset: BioMart dataset name
     """
 
-    def __init__(self, dataset: str):
-        super().__init__()
+    def __init__(self, dataset: str, save: bool = False):
+        super().__init__(save=save)
         self.dataset = dataset
 
     def find_filters(self) -> pd.DataFrame:
@@ -250,6 +263,9 @@ def find_filters(self) -> pd.DataFrame:
         df["dataset"] = self.dataset
         df.columns = ["Filter_ID", "Filter_type",
                       "Filter_description", "Dataset_ID"]
+        df.replace(pd.np.nan, "", inplace=True)
+        if self.save:
+            df.to_csv("apybiomart_filters.csv", index=False)
 
         return df
 
@@ -304,8 +320,9 @@ class Query(_Server):
     def __init__(self,
                  attributes: List[str],
                  filters: Dict[str, Union[str, int, list, tuple, bool]],
-                 dataset: str):
-        super().__init__()
+                 dataset: str,
+                 save: bool = False):
+        super().__init__(save=save)
         self.attributes = attributes
         self.filters = filters
         self.dataset = dataset
@@ -357,6 +374,10 @@ def query(self) -> pd.DataFrame:
         # Type error is raised of a data type is not understood by pandas
         except TypeError as err:
             raise ValueError("Non valid data type is used in dtypes")
+        result.replace(pd.np.nan, "", inplace=True)
+
+        if self.save:
+            result.to_csv("apybiomart_query.csv", index=False)
 
         return result
 
@@ -407,6 +428,10 @@ async def aquery(self) -> pd.DataFrame:
         # Type error is raised of a data type is not understood by pandas
         except TypeError as err:
             raise ValueError("Non valid data type is used in dtypes")
+        result.replace(pd.np.nan, "", inplace=True)
+
+        if self.save:
+            result.to_csv("apybiomart_aquery.csv", index=False)
 
         return result
 
diff --git a/apybiomart/commands/attributes.py b/apybiomart/commands/attributes.py
index 8f25e8a..383f075 100644
--- a/apybiomart/commands/attributes.py
+++ b/apybiomart/commands/attributes.py
@@ -10,10 +10,12 @@
 @click.command("attributes")
 @click.option("--dataset", default="hsapiens_gene_ensembl", type=str,
               help="BioMart dataset name (default: 'hsapiens_gene_ensembl')")
-def cli_attributes(dataset):
+@click.option("--save", "-s", default=False, is_flag=True,
+              help="Save results to a CSV file [default: False]")
+def cli_attributes(dataset, save):
     """Retrieve and list available attributes for a given mart."""
     pd.set_option("max_rows", 999)
-    attributes = find_attributes(dataset)
+    attributes = find_attributes(dataset, save=save)
     attributes.columns = [col.replace("_", " ") for col in attributes.columns]
     click.echo(attributes)
     return 0
diff --git a/apybiomart/commands/datasets.py b/apybiomart/commands/datasets.py
index 2f05b71..105aba1 100644
--- a/apybiomart/commands/datasets.py
+++ b/apybiomart/commands/datasets.py
@@ -10,10 +10,12 @@
 @click.command("datasets")
 @click.option("--mart", default="ENSEMBL_MART_ENSEMBL", type=str,
               help="BioMart mart name (default: 'ENSEMBL_MART_ENSEMBL')")
-def cli_datasets(mart):
+@click.option("--save", "-s", default=False, is_flag=True,
+              help="Save results to a CSV file [default: False]")
+def cli_datasets(mart, save):
     """Retrieve and list available datasets for a given mart."""
     pd.set_option("max_rows", 999)
-    datasets = find_datasets(mart)
+    datasets = find_datasets(mart, save=save)
     datasets.columns = [col.replace("_", " ") for col in datasets.columns]
     click.echo(datasets)
     return 0
diff --git a/apybiomart/commands/filters.py b/apybiomart/commands/filters.py
index bc458d3..ae53583 100644
--- a/apybiomart/commands/filters.py
+++ b/apybiomart/commands/filters.py
@@ -10,10 +10,12 @@
 @click.command("filters")
 @click.option("--dataset", default="hsapiens_gene_ensembl", type=str,
               help="BioMart dataset name (default: 'hsapiens_gene_ensembl')")
-def cli_filters(dataset):
+@click.option("--save", "-s", default=False, is_flag=True,
+              help="Save results to a CSV file [default: False]")
+def cli_filters(dataset, save):
     """Retrieve and list available filters for a given mart."""
     pd.set_option("max_rows", 999)
-    filters = find_filters(dataset)
+    filters = find_filters(dataset, save=save)
     filters.columns = [col.replace("_", " ") for col in filters.columns]
     click.echo(filters)
     return 0
diff --git a/apybiomart/commands/marts.py b/apybiomart/commands/marts.py
index 75410fb..e523588 100644
--- a/apybiomart/commands/marts.py
+++ b/apybiomart/commands/marts.py
@@ -8,10 +8,12 @@
 
 
 @click.command("marts")
-def cli_marts():
+@click.option("--save", "-s", default=False, is_flag=True,
+              help="Save results to a CSV file [default: False]")
+def cli_marts(save):
     """Retrieve and list available marts."""
     pd.set_option("max_rows", 999)
-    marts = find_marts()
+    marts = find_marts(save=save)
     marts.columns = [col.replace("_", " ") for col in marts.columns]
     click.echo(marts)
     return 0
diff --git a/apybiomart/tests/create_suite.py b/apybiomart/tests/create_suite.py
index e156422..f3a3288 100644
--- a/apybiomart/tests/create_suite.py
+++ b/apybiomart/tests/create_suite.py
@@ -1,9 +1,9 @@
 #!/usr/bin/env python
 # -*- coding: UTF-8 -*-
 # Created by Roberto Preste
-import asyncio
 import os
-import pandas as pd
+
+import asyncio
 import apybiomart as apy
 
 DATADIR = os.path.join(os.path.dirname(os.path.realpath(__file__)), "data")
diff --git a/apybiomart/tests/data/attributes_chircus_snp.pkl b/apybiomart/tests/data/attributes_chircus_snp.pkl
index ba548ab..37d3445 100644
Binary files a/apybiomart/tests/data/attributes_chircus_snp.pkl and b/apybiomart/tests/data/attributes_chircus_snp.pkl differ
diff --git a/apybiomart/tests/data/attributes_closure_ECO.pkl b/apybiomart/tests/data/attributes_closure_ECO.pkl
index e5012ba..40d1ff1 100644
Binary files a/apybiomart/tests/data/attributes_closure_ECO.pkl and b/apybiomart/tests/data/attributes_closure_ECO.pkl differ
diff --git a/apybiomart/tests/data/attributes_hsapiens_encode.pkl b/apybiomart/tests/data/attributes_hsapiens_encode.pkl
index 1464873..baa6689 100644
Binary files a/apybiomart/tests/data/attributes_hsapiens_encode.pkl and b/apybiomart/tests/data/attributes_hsapiens_encode.pkl differ
diff --git a/apybiomart/tests/data/attributes_hsapiens_gene_ensembl.pkl b/apybiomart/tests/data/attributes_hsapiens_gene_ensembl.pkl
index 8ae48d5..6c5fde1 100644
Binary files a/apybiomart/tests/data/attributes_hsapiens_gene_ensembl.pkl and b/apybiomart/tests/data/attributes_hsapiens_gene_ensembl.pkl differ
diff --git a/apybiomart/tests/data/attributes_hsapiens_peak.pkl b/apybiomart/tests/data/attributes_hsapiens_peak.pkl
index 6f13a3d..85bd1cb 100644
Binary files a/apybiomart/tests/data/attributes_hsapiens_peak.pkl and b/apybiomart/tests/data/attributes_hsapiens_peak.pkl differ
diff --git a/apybiomart/tests/data/datasets_ensembl.pkl b/apybiomart/tests/data/datasets_ensembl.pkl
index c896271..8116ed9 100644
Binary files a/apybiomart/tests/data/datasets_ensembl.pkl and b/apybiomart/tests/data/datasets_ensembl.pkl differ
diff --git a/apybiomart/tests/data/datasets_funcgen.pkl b/apybiomart/tests/data/datasets_funcgen.pkl
index 92ef87e..7098d8d 100644
Binary files a/apybiomart/tests/data/datasets_funcgen.pkl and b/apybiomart/tests/data/datasets_funcgen.pkl differ
diff --git a/apybiomart/tests/data/datasets_genomic.pkl b/apybiomart/tests/data/datasets_genomic.pkl
index 958fb47..29b85f1 100644
Binary files a/apybiomart/tests/data/datasets_genomic.pkl and b/apybiomart/tests/data/datasets_genomic.pkl differ
diff --git a/apybiomart/tests/data/datasets_mouse.pkl b/apybiomart/tests/data/datasets_mouse.pkl
index a12336d..a10006a 100644
Binary files a/apybiomart/tests/data/datasets_mouse.pkl and b/apybiomart/tests/data/datasets_mouse.pkl differ
diff --git a/apybiomart/tests/data/datasets_ontology.pkl b/apybiomart/tests/data/datasets_ontology.pkl
index bc196c8..2302037 100644
Binary files a/apybiomart/tests/data/datasets_ontology.pkl and b/apybiomart/tests/data/datasets_ontology.pkl differ
diff --git a/apybiomart/tests/data/datasets_sequence.pkl b/apybiomart/tests/data/datasets_sequence.pkl
index a1d5b9b..ad52c34 100644
Binary files a/apybiomart/tests/data/datasets_sequence.pkl and b/apybiomart/tests/data/datasets_sequence.pkl differ
diff --git a/apybiomart/tests/data/datasets_snp.pkl b/apybiomart/tests/data/datasets_snp.pkl
index d6a399a..e590cde 100644
Binary files a/apybiomart/tests/data/datasets_snp.pkl and b/apybiomart/tests/data/datasets_snp.pkl differ
diff --git a/apybiomart/tests/data/filters_chircus_snp.pkl b/apybiomart/tests/data/filters_chircus_snp.pkl
index 050b4ac..67d78e5 100644
Binary files a/apybiomart/tests/data/filters_chircus_snp.pkl and b/apybiomart/tests/data/filters_chircus_snp.pkl differ
diff --git a/apybiomart/tests/data/filters_closure_ECO.pkl b/apybiomart/tests/data/filters_closure_ECO.pkl
index efb9b56..2c3b987 100644
Binary files a/apybiomart/tests/data/filters_closure_ECO.pkl and b/apybiomart/tests/data/filters_closure_ECO.pkl differ
diff --git a/apybiomart/tests/data/filters_hsapiens_encode.pkl b/apybiomart/tests/data/filters_hsapiens_encode.pkl
index f31096a..ae57d1f 100644
Binary files a/apybiomart/tests/data/filters_hsapiens_encode.pkl and b/apybiomart/tests/data/filters_hsapiens_encode.pkl differ
diff --git a/apybiomart/tests/data/filters_hsapiens_gene_ensembl.pkl b/apybiomart/tests/data/filters_hsapiens_gene_ensembl.pkl
index 69a9cf2..85ce42c 100644
Binary files a/apybiomart/tests/data/filters_hsapiens_gene_ensembl.pkl and b/apybiomart/tests/data/filters_hsapiens_gene_ensembl.pkl differ
diff --git a/apybiomart/tests/data/filters_hsapiens_peak.pkl b/apybiomart/tests/data/filters_hsapiens_peak.pkl
index c1a64ce..74240e5 100644
Binary files a/apybiomart/tests/data/filters_hsapiens_peak.pkl and b/apybiomart/tests/data/filters_hsapiens_peak.pkl differ
diff --git a/apybiomart/tests/test_aquery.py b/apybiomart/tests/test_aquery.py
index 67a0aa7..aed6406 100644
--- a/apybiomart/tests/test_aquery.py
+++ b/apybiomart/tests/test_aquery.py
@@ -1,9 +1,13 @@
 #!/usr/bin/env python
 # -*- coding: UTF-8 -*-
 # Created by Roberto Preste
+import os
 import pytest
+
 import asyncio
+import pandas as pd
 from pandas.testing import assert_frame_equal
+
 from apybiomart import aquery
 
 
@@ -22,6 +26,28 @@ def test_aquery_default(df_query_ensembl_hsapiens_gene_chrom_2):
     assert_frame_equal(result, expect)
 
 
+def test_aquery_save(df_query_ensembl_hsapiens_gene_chrom_2):
+    """Test the saved async query results for the default dataset
+    (hsapiens_gene_ensembl)."""
+    expect = (df_query_ensembl_hsapiens_gene_chrom_2
+              .reset_index(drop=True))
+
+    loop = asyncio.get_event_loop()
+    result = loop.run_until_complete(
+        aquery(attributes=["ensembl_gene_id", "external_gene_name"],
+               filters={"chromosome_name": "2"},
+               save=True)
+    )
+    saved = (pd.read_csv("apybiomart_aquery.csv")
+             .replace(pd.np.nan, "")
+             .reset_index(drop=True))
+
+    try:
+        assert_frame_equal(saved, expect)
+    finally:
+        os.remove("apybiomart_aquery.csv")
+
+
 def test_aquery_default_int(df_query_ensembl_hsapiens_gene_chrom_2):
     """Test the async query results for the default dataset
     (hsapiens_gene_ensembl) with int filters parameter."""
diff --git a/apybiomart/tests/test_attributes.py b/apybiomart/tests/test_attributes.py
index 735364a..50eb37f 100644
--- a/apybiomart/tests/test_attributes.py
+++ b/apybiomart/tests/test_attributes.py
@@ -1,8 +1,12 @@
 #!/usr/bin/env python
 # -*- coding: UTF-8 -*-
 # Created by Roberto Preste
+import os
 import pytest
+
+import pandas as pd
 from pandas.testing import assert_frame_equal
+
 from apybiomart import find_attributes
 
 
@@ -19,6 +23,25 @@ def test_find_attributes_default(df_attributes_ensembl_hsapiens_gene):
     assert_frame_equal(result, expect)
 
 
+def test_find_attributes_save(df_attributes_ensembl_hsapiens_gene):
+    """Test the available attributes returned by find_attributes(save=True)
+    for the default dataset (hsapiens_gene_ensembl)."""
+    expect = (df_attributes_ensembl_hsapiens_gene
+              .sort_values(by="Attribute_ID", axis=0)
+              .reset_index(drop=True))
+    _ = find_attributes(save=True)
+    saved = pd.read_csv("apybiomart_attributes.csv")
+    result = (saved
+              .replace(pd.np.nan, "")
+              .sort_values(by="Attribute_ID", axis=0)
+              .reset_index(drop=True))
+
+    try:
+        assert_frame_equal(result, expect)
+    finally:
+        os.remove("apybiomart_attributes.csv")
+
+
 def test_find_attributes_ensembl(df_attributes_ensembl_hsapiens_gene):
     """Test the available attributes returned by find_attributes() for the
     hsapiens_gene_ensembl dataset."""
diff --git a/apybiomart/tests/test_cli_attributes.py b/apybiomart/tests/test_cli_attributes.py
index 28c4a12..039cda1 100644
--- a/apybiomart/tests/test_cli_attributes.py
+++ b/apybiomart/tests/test_cli_attributes.py
@@ -1,7 +1,9 @@
 #!/usr/bin/env python
 # -*- coding: UTF-8 -*-
 # Created by Roberto Preste
+import os
 import pytest
+
 from click.testing import CliRunner
 
 from apybiomart import cli
@@ -18,6 +20,18 @@ def test_cli_attributes_default():
     assert "hsapiens_gene_ensembl" in result.output
 
 
+def test_cli_attributes_save():
+    """Test the saved attributes returned by apybiomart attributes for the
+    default dataset (hsapiens_gene_ensembl)."""
+    runner = CliRunner()
+    result = runner.invoke(cli.main, ["attributes", "--save"])
+    try:
+        assert result.exit_code == 0
+        assert os.path.isfile("apybiomart_attributes.csv")
+    finally:
+        os.remove("apybiomart_attributes.csv")
+
+
 def test_cli_attributes_ontology():
     """Test the available attributes returned by apybiomart attributes for the
     closure_ECO dataset."""
diff --git a/apybiomart/tests/test_cli_datasets.py b/apybiomart/tests/test_cli_datasets.py
index 0d8a537..6dd6671 100644
--- a/apybiomart/tests/test_cli_datasets.py
+++ b/apybiomart/tests/test_cli_datasets.py
@@ -1,7 +1,9 @@
 #!/usr/bin/env python
 # -*- coding: UTF-8 -*-
 # Created by Roberto Preste
+import os
 import pytest
+
 from click.testing import CliRunner
 
 from apybiomart import cli
@@ -18,6 +20,18 @@ def test_cli_datasets_default():
     assert "ENSEMBL_MART_ENSEMBL" in result.output
 
 
+def test_cli_datasets_save():
+    """Test the saved datasets returned by apybiomart datasets for the
+    default mart (ENSEMBL_MART_ENSEMBL)."""
+    runner = CliRunner()
+    result = runner.invoke(cli.main, ["datasets", "--save"])
+    try:
+        assert result.exit_code == 0
+        assert os.path.isfile("apybiomart_datasets.csv")
+    finally:
+        os.remove("apybiomart_datasets.csv")
+
+
 def test_cli_datasets_mouse():
     """Test the available datasets returned by apybiomart datasets for the
     ENSEMBL_MART_MOUSE mart."""
diff --git a/apybiomart/tests/test_cli_filters.py b/apybiomart/tests/test_cli_filters.py
index d71aaa2..0b3e95f 100644
--- a/apybiomart/tests/test_cli_filters.py
+++ b/apybiomart/tests/test_cli_filters.py
@@ -1,7 +1,9 @@
 #!/usr/bin/env python
 # -*- coding: UTF-8 -*-
 # Created by Roberto Preste
+import os
 import pytest
+
 from click.testing import CliRunner
 
 from apybiomart import cli
@@ -18,6 +20,18 @@ def test_cli_filters_default():
     assert "hsapiens_gene_ensembl" in result.output
 
 
+def test_cli_filters_saved():
+    """Test the saved attributes returned by apybiomart filters for the
+    default dataset (hsapiens_gene_ensembl)."""
+    runner = CliRunner()
+    result = runner.invoke(cli.main, ["filters", "--save"])
+    try:
+        assert result.exit_code == 0
+        assert os.path.isfile("apybiomart_filters.csv")
+    finally:
+        os.remove("apybiomart_filters.csv")
+
+
 def test_cli_filters_ontology():
     """Test the available attributes returned by apybiomart filters for the
     closure_ECO dataset."""
diff --git a/apybiomart/tests/test_cli_marts.py b/apybiomart/tests/test_cli_marts.py
index 059dcc2..5c0b61b 100644
--- a/apybiomart/tests/test_cli_marts.py
+++ b/apybiomart/tests/test_cli_marts.py
@@ -1,7 +1,9 @@
 #!/usr/bin/env python
 # -*- coding: UTF-8 -*-
 # Created by Roberto Preste
+import os
 import pytest
+
 from click.testing import CliRunner
 
 from apybiomart import cli
@@ -15,3 +17,14 @@ def test_cli_marts():
     assert "Mart ID" in result.output
     assert "ENSEMBL_MART_ENSEMBL" in result.output
     assert "Ensembl Genes 99" in result.output
+
+
+def test_cli_marts_save():
+    """Test the available marts saved by apybiomart marts."""
+    runner = CliRunner()
+    result = runner.invoke(cli.main, ["marts", "--save"])
+    try:
+        assert result.exit_code == 0
+        assert os.path.isfile("apybiomart_marts.csv")
+    finally:
+        os.remove("apybiomart_marts.csv")
diff --git a/apybiomart/tests/test_datasets.py b/apybiomart/tests/test_datasets.py
index 7d6a131..4a44937 100644
--- a/apybiomart/tests/test_datasets.py
+++ b/apybiomart/tests/test_datasets.py
@@ -1,8 +1,12 @@
 #!/usr/bin/env python
 # -*- coding: UTF-8 -*-
 # Created by Roberto Preste
+import os
 import pytest
+
+import pandas as pd
 from pandas.testing import assert_frame_equal
+
 from apybiomart import find_datasets
 
 
@@ -19,6 +23,25 @@ def test_find_datasets_default(df_datasets_ensembl):
     assert_frame_equal(result, expect)
 
 
+def test_find_datasets_save(df_datasets_ensembl):
+    """Test the available datasets returned by find_datasets(save=True) for
+    the default mart (ENSEMBL_MART_ENSEMBL)."""
+    expect = (df_datasets_ensembl
+              .sort_values(by="Dataset_ID", axis=0)
+              .reset_index(drop=True))
+    _ = find_datasets(save=True)
+    saved = pd.read_csv("apybiomart_datasets.csv")
+    result = (saved
+              .replace(pd.np.nan, "")
+              .sort_values(by="Dataset_ID", axis=0)
+              .reset_index(drop=True))
+
+    try:
+        assert_frame_equal(result, expect)
+    finally:
+        os.remove("apybiomart_datasets.csv")
+
+
 def test_find_datasets_ensembl(df_datasets_ensembl):
     """Test the available datasets returned by find_datasets() for the
     ENSEMBL_MART_ENSEMBL mart."""
diff --git a/apybiomart/tests/test_filters.py b/apybiomart/tests/test_filters.py
index 75f8b7d..6a5047c 100644
--- a/apybiomart/tests/test_filters.py
+++ b/apybiomart/tests/test_filters.py
@@ -1,8 +1,12 @@
 #!/usr/bin/env python
 # -*- coding: UTF-8 -*-
 # Created by Roberto Preste
+import os
 import pytest
+
+import pandas as pd
 from pandas.testing import assert_frame_equal
+
 from apybiomart import find_filters
 
 
@@ -19,6 +23,25 @@ def test_find_filters_default(df_filters_ensembl_hsapiens_gene):
     assert_frame_equal(result, expect)
 
 
+def test_find_filters_save(df_filters_ensembl_hsapiens_gene):
+    """Test the available filters returned by find_filters(save=True) for the
+    default dataset (hsapiens_gene_ensembl)."""
+    expect = (df_filters_ensembl_hsapiens_gene
+              .sort_values(by="Filter_ID", axis=0)
+              .reset_index(drop=True))
+    _ = find_filters(save=True)
+    saved = pd.read_csv("apybiomart_filters.csv")
+    result = (saved
+              .replace(pd.np.nan, "")
+              .sort_values(by="Filter_ID", axis=0)
+              .reset_index(drop=True))
+
+    try:
+        assert_frame_equal(result, expect)
+    finally:
+        os.remove("apybiomart_filters.csv")
+
+
 def test_find_filters_ensembl(df_filters_ensembl_hsapiens_gene):
     """Test the available filters returned by find_filters() for the
     hsapiens_gene_ensembl dataset."""
diff --git a/apybiomart/tests/test_marts.py b/apybiomart/tests/test_marts.py
index 7787b73..cbd31cf 100644
--- a/apybiomart/tests/test_marts.py
+++ b/apybiomart/tests/test_marts.py
@@ -1,8 +1,12 @@
 #!/usr/bin/env python
 # -*- coding: UTF-8 -*-
 # Created by Roberto Preste
+import os
 import pytest
+
+import pandas as pd
 from pandas.testing import assert_frame_equal
+
 from apybiomart import find_marts
 
 
@@ -17,3 +21,20 @@ def test_find_marts(df_marts):
 
     assert_frame_equal(result, expect)
 
+
+def test_find_marts_save(df_marts):
+    """Test the available marts returned by find_marts(save=True)."""
+    expect = (df_marts
+              .sort_values(by="Mart_ID", axis=0)
+              .reset_index(drop=True))
+    _ = find_marts(save=True)
+    saved = pd.read_csv("apybiomart_marts.csv")
+    result = (saved
+              .replace(pd.np.nan, "")
+              .sort_values(by="Mart_ID", axis=0)
+              .reset_index(drop=True))
+
+    try:
+        assert_frame_equal(result, expect)
+    finally:
+        os.remove("apybiomart_marts.csv")
diff --git a/apybiomart/tests/test_query.py b/apybiomart/tests/test_query.py
index 6d43342..c8d0171 100644
--- a/apybiomart/tests/test_query.py
+++ b/apybiomart/tests/test_query.py
@@ -1,8 +1,12 @@
 #!/usr/bin/env python
 # -*- coding: UTF-8 -*-
 # Created by Roberto Preste
+import os
 import pytest
+
+import pandas as pd
 from pandas.testing import assert_frame_equal
+
 from apybiomart import query
 
 
@@ -17,6 +21,25 @@ def test_query_default(df_query_ensembl_hsapiens_gene_chrom_2):
     assert_frame_equal(result, expect)
 
 
+def test_query_save(df_query_ensembl_hsapiens_gene_chrom_2):
+    """Test the saved query results for the default dataset
+    (hsapiens_gene_ensembl)."""
+    expect = (df_query_ensembl_hsapiens_gene_chrom_2
+              .reset_index(drop=True))
+    _ = query(attributes=["ensembl_gene_id", "external_gene_name"],
+              filters={"chromosome_name": "2"},
+              save=True)
+    saved = pd.read_csv("apybiomart_query.csv")
+    result = (saved
+              .replace(pd.np.nan, "")
+              .reset_index(drop=True))
+
+    try:
+        assert_frame_equal(result, expect)
+    finally:
+        os.remove("apybiomart_query.csv")
+
+
 def test_query_default_int(df_query_ensembl_hsapiens_gene_chrom_2):
     """Test the query results for the default dataset (hsapiens_gene_ensembl)
     with int filters parameter."""