diff --git a/pandas/core/generic.py b/pandas/core/generic.py
index 5231fa82c1a73..6c80ab9d87e33 100644
--- a/pandas/core/generic.py
+++ b/pandas/core/generic.py
@@ -4633,14 +4633,15 @@ def tshift(self, periods=1, freq=None, axis=0):
 
     def truncate(self, before=None, after=None, axis=None, copy=True):
         """Truncates a sorted NDFrame before and/or after some particular
-        dates.
+        index value. If the axis contains only datetime values, before/after
+        parameters are converted to datetime values.
 
         Parameters
         ----------
         before : date
-            Truncate before date
+            Truncate before index value
         after : date
-            Truncate after date
+            Truncate after index value
         axis : the truncation axis, defaults to the stat axis
         copy : boolean, default is True,
             return a copy of the truncated section
diff --git a/pandas/tests/test_generic.py b/pandas/tests/test_generic.py
index 1c2494e7d6b09..d10494210d04e 100644
--- a/pandas/tests/test_generic.py
+++ b/pandas/tests/test_generic.py
@@ -595,6 +595,22 @@ def test_clip(self):
                                lower=lower, upper=upper,
                                axis=bad_axis)
 
+    def test_truncate_outofbounds_small(self):
+        # GH11382
+        shape = [int(2e3)] + ([1] * (self._ndim-1))
+        small = self._construct(shape, dtype='int8')
+        self._compare(small.truncate(), small)
+        self._compare(small.truncate(before=0, after=3e3), small)
+        self._compare(small.truncate(before=-1, after=2e3), small)
+
+    def test_truncate_outofbounds_big(self):
+        # GH11382
+        shape = [int(2e6)] + ([1] * (self._ndim-1))
+        big = self._construct(shape, dtype='int8')
+        self._compare(big.truncate(), big)
+        self._compare(big.truncate(before=0, after=3e6), big)
+        self._compare(big.truncate(before=-1, after=2e6), big)
+
     def test_numpy_clip(self):
         lower = 1
         upper = 3
@@ -809,6 +825,17 @@ def test_describe_none(self):
         expected = Series([0, 0], index=['count', 'unique'], name='None')
         assert_series_equal(noneSeries.describe(), expected)
 
+    def test_truncate_outofbounds(self):
+        # GH11382
+        small = pd.Series(data=range(int(2e3)), index=range(int(2e3)))
+        assert_series_equal(small.truncate(), small)
+        assert_series_equal(small.truncate(before=0, after=3e3), small)
+        assert_series_equal(small.truncate(before=-1, after=2e3), small)
+        big = pd.Series(data=range(int(2e6)), index=range(int(2e6)))
+        assert_series_equal(big.truncate(), big)
+        assert_series_equal(big.truncate(before=0, after=3e6), big)
+        assert_series_equal(big.truncate(before=-1, after=2e6), big)
+
     def test_to_xarray(self):
 
         tm._skip_if_no_xarray()