Index: Doc/library/tarfile.rst
===================================================================
--- Doc/library/tarfile.rst	(revision 78510)
+++ Doc/library/tarfile.rst	(working copy)
@@ -650,6 +650,14 @@
        tar.add(name)
    tar.close()
 
+The same example using :func:`tarfile.open` as a context manager 
+(see :ref:`typecontextmanager`)::
+
+    import tarfile
+    with tarfile.open("sample.tar", "w") as tar:
+        for name in ["foo", "bar", "quux"]:
+            tar.add(name)
+
 How to read a gzip compressed tar archive and display some member information::
 
    import tarfile
Index: Lib/tarfile.py
===================================================================
--- Lib/tarfile.py	(revision 78510)
+++ Lib/tarfile.py	(working copy)
@@ -2411,6 +2411,18 @@
         """
         if level <= self.debug:
             print >> sys.stderr, msg
+
+    def __enter__(self):
+        """Enter the runtime context for this tarfile, if the tarfile
+           is in a valid state.  Otherwise, an IOError is raised.
+        """
+        self._check()
+        return self
+
+    def __exit__(self, type, value, traceback):
+        """Exit the runtime context without supressing any exceptions.
+        """
+        self.close()
 # class TarFile
 
 class TarIter:
Index: Lib/test/test_tarfile.py
===================================================================
--- Lib/test/test_tarfile.py	(revision 78510)
+++ Lib/test/test_tarfile.py	(working copy)
@@ -327,7 +327,34 @@
         finally:
             os.remove(empty)
 
+    def test_context_manager(self):
+        with tarfile.open(tarname) as tar:
+            self.assertFalse(tar.closed, "closed inside runtime context")
+        self.assertTrue(tar.closed, "context manager failed")
 
+    def test_context_manager_closed(self):
+        tar = tarfile.open(tarname)
+        tar.close()
+        with self.assertRaises(IOError):
+            with tar: 
+                pass
+
+    def test_context_manager_exception(self):
+        # Create a unique exception type so that we
+        # can guarantee the exception source.
+        class TarfileTestException(Exception): pass
+
+        try:
+            with tarfile.open(tarname) as tar:
+                raise TarfileTestException
+        except TarfileTestException:
+            self.assertTrue(tar.closed, "context manager failed")
+        except:
+            self.fail("wrong exception raised in context manager")
+        else:
+            self.fail("exception not reraised in context manager")
+
+
 class StreamReadTest(CommonReadTest):
 
     mode="r|"