diff --git a/pandas/core/strings.py b/pandas/core/strings.py
index 604ee47c8fee7..aa73d09194248 100644
--- a/pandas/core/strings.py
+++ b/pandas/core/strings.py
@@ -654,6 +654,9 @@ def str_split(arr, pat=None, n=None, return_type='series'):
     if return_type in ('frame', 'expand')  and isinstance(arr, Index):
         raise ValueError("return_type='frame' is not supported for string "
                          "methods on Index")
+    if return_type in ('series', 'index', 'frame'):
+        warnings.warn(("'series', 'index' and 'frame' are  deprecated. Please use 'same' or 'expand' instead"),
+            FutureWarning)
     if pat is None:
         if n is None or n == 0:
             n = -1
diff --git a/pandas/tests/test_index.py b/pandas/tests/test_index.py
index 7267924baf023..159635da5d505 100644
--- a/pandas/tests/test_index.py
+++ b/pandas/tests/test_index.py
@@ -1226,7 +1226,6 @@ def test_str_attribute(self):
             idx.str.split(return_type='frame')
         with self.assertRaisesRegexp(ValueError, 'not supported'):
             idx.str.split(return_type='expand')
-
         # test boolean case, should return np.array instead of boolean Index
         idx = Index(['a1', 'a2', 'b1', 'b2'])
         expected = np.array([True, True, False, False])