diff --git a/README.rst b/README.rst
index 0fdc412f9..0b04c1e5f 100644
--- a/README.rst
+++ b/README.rst
@@ -5,6 +5,10 @@ PyMongo
 :Author: Mike Dirolf
 :Maintainer: Bernie Hackett <bernie@mongodb.com>
 
+.. warning:: PyMongo 2.x is in maintenance mode. Support for new MongoDB
+  features ended with the release of MongoDB 3.0 and PyMongo 2.8. Users are
+  strongly encouraged to upgrade to PyMongo 3.x.
+
 About
 =====