diff -r ac27d979078a Lib/unittest/mock.py
--- a/Lib/unittest/mock.py	Thu Sep 05 00:23:08 2013 +0200
+++ b/Lib/unittest/mock.py	Mon Sep 09 11:39:05 2013 +0200
@@ -495,8 +495,12 @@
     side_effect = property(__get_side_effect, __set_side_effect)
 
 
-    def reset_mock(self):
+    def reset_mock(self, visited=[]):
         "Restore the mock object to its initial state."
+        if id(self) in visited:
+            return
+        visited.append(id(self))
+
         self.called = False
         self.call_args = None
         self.call_count = 0
@@ -507,11 +511,11 @@
         for child in self._mock_children.values():
             if isinstance(child, _SpecState):
                 continue
-            child.reset_mock()
+            child.reset_mock(visited)
 
         ret = self._mock_return_value
         if _is_instance_mock(ret) and ret is not self:
-            ret.reset_mock()
+            ret.reset_mock(visited)
 
 
     def configure_mock(self, **kwargs):
diff -r ac27d979078a Misc/NEWS
--- a/Misc/NEWS	Thu Sep 05 00:23:08 2013 +0200
+++ b/Misc/NEWS	Mon Sep 09 11:39:05 2013 +0200
@@ -178,6 +178,9 @@
 
 - Issue #8860: Fixed rounding in timedelta constructor.
 
+- Issue #18622: Fixed the infinite recursion in `reset_mock()`. Solved by tracking
+  a set of visited ids.
+
 Tests
 -----