diff --git a/pandas/io/excel.py b/pandas/io/excel.py
index 5e4dd4379a8e3..89ce5aec8d264 100644
--- a/pandas/io/excel.py
+++ b/pandas/io/excel.py
@@ -29,6 +29,7 @@
 from warnings import warn
 from distutils.version import LooseVersion
 from pandas.util.decorators import Appender
+from textwrap import fill
 
 __all__ = ["read_excel", "ExcelWriter", "ExcelFile"]
 
@@ -97,7 +98,7 @@
 na_values : scalar, str, list-like, or dict, default None
     Additional strings to recognize as NA/NaN. If dict passed, specific
     per-column NA values. By default the following values are interpreted
-    as NaN: '""" + "', '".join(sorted(_NA_VALUES)) + """'.
+    as NaN: '""" + fill("', '".join(sorted(_NA_VALUES)), 70) + """'.
 thousands : str, default None
     Thousands separator for parsing string columns to numeric.  Note that
     this parameter is only necessary for columns stored as TEXT in Excel,
diff --git a/pandas/io/parsers.py b/pandas/io/parsers.py
index e765ebc36e33e..2ef0cbb0076fe 100755
--- a/pandas/io/parsers.py
+++ b/pandas/io/parsers.py
@@ -7,6 +7,7 @@
 import csv
 import warnings
 import datetime
+from textwrap import fill
 
 import numpy as np
 
@@ -132,7 +133,7 @@
 na_values : scalar, str, list-like, or dict, default None
     Additional strings to recognize as NA/NaN. If dict passed, specific
     per-column NA values.  By default the following values are interpreted as
-    NaN: `'""" + "'`, `'".join(sorted(_NA_VALUES)) + """'`.
+    NaN: '""" + fill("', '".join(sorted(_NA_VALUES)), 70) + """'`.
 keep_default_na : bool, default True
     If na_values are specified and keep_default_na is False the default NaN
     values are overridden, otherwise they're appended to.