diff -r 540a9c69c2ea Doc/library/selectors.rst
--- a/Doc/library/selectors.rst	Fri Sep 13 19:53:08 2013 +0200
+++ b/Doc/library/selectors.rst	Sat Oct 05 16:32:42 2013 +0200
@@ -164,6 +164,10 @@
       This returns the :class:`SelectorKey` instance associated to this file
       object, or raises :exc:`KeyError` if the file object is not registered.
 
+   .. method:: keys()
+
+      Return all the registered keys.
+
 
 .. class:: DefaultSelector()
 
diff -r 540a9c69c2ea Lib/selectors.py
--- a/Lib/selectors.py	Fri Sep 13 19:53:08 2013 +0200
+++ b/Lib/selectors.py	Sat Oct 05 16:32:42 2013 +0200
@@ -162,6 +162,14 @@
         except KeyError:
             raise KeyError("{!r} is not registered".format(fileobj)) from None
 
+    def keys(self):
+        """Return all the registered keys.
+
+        Returns:
+        set of registered keys
+        """
+        return set(self._fd_to_key.values())
+
     def __enter__(self):
         return self
 
diff -r 540a9c69c2ea Lib/test/test_selectors.py
--- a/Lib/test/test_selectors.py	Fri Sep 13 19:53:08 2013 +0200
+++ b/Lib/test/test_selectors.py	Sat Oct 05 16:32:42 2013 +0200
@@ -153,6 +153,21 @@
         # unknown file obj
         self.assertRaises(KeyError, s.get_key, 999999)
 
+    def test_keys(self):
+        s = self.SELECTOR()
+        self.addCleanup(s.close)
+
+        rd, wr = socketpair()
+        self.addCleanup(rd.close)
+        self.addCleanup(wr.close)
+
+        key1 = s.register(rd, selectors.EVENT_READ)
+        key2 = s.register(wr, selectors.EVENT_WRITE)
+        self.assertEqual(set([key1, key2]), s.keys())
+
+        s.unregister(rd)
+        self.assertEqual(set([key2]), s.keys())
+
     def test_select(self):
         s = self.SELECTOR()
         self.addCleanup(s.close)