diff -r e78e35954fbf Lib/multiprocessing/sharedctypes.py
--- a/Lib/multiprocessing/sharedctypes.py	Thu Mar 17 12:59:38 2011 -0400
+++ b/Lib/multiprocessing/sharedctypes.py	Fri Mar 25 14:39:58 2011 -0500
@@ -34,6 +34,7 @@
 
 import sys
 import ctypes
+from operator import index
 import weakref
 
 from multiprocessing import heap, RLock
@@ -78,14 +79,17 @@
     Returns a ctypes array allocated from shared memory
     '''
     type_ = typecode_to_type.get(typecode_or_type, typecode_or_type)
-    if isinstance(size_or_initializer, int):
-        type_ = type_ * size_or_initializer
-        return _new_value(type_)
-    else:
+    try:
+        size = index(size_or_initializer)
+    except TypeError:
+        # Initializer.
         type_ = type_ * len(size_or_initializer)
         result = _new_value(type_)
         result.__init__(*size_or_initializer)
         return result
+    else:
+        type_ = type_ * size
+        return _new_value(type_)
 
 def Value(typecode_or_type, *args, **kwds):
     '''
diff -r e78e35954fbf Lib/test/test_multiprocessing.py
--- a/Lib/test/test_multiprocessing.py	Thu Mar 17 12:59:38 2011 -0400
+++ b/Lib/test/test_multiprocessing.py	Fri Mar 25 14:39:58 2011 -0500
@@ -918,6 +918,13 @@
         self.test_array(raw=True)
 
     @unittest.skipIf(c_int is None, "requires _ctypes")
+    def test_array_accepts_long(self):
+        arr = self.Array('i', 10L)
+        self.assertEqual(len(arr), 10)
+        raw_arr = self.RawArray('i', 10L)
+        self.assertEqual(len(raw_arr), 10)
+
+    @unittest.skipIf(c_int is None, "requires _ctypes")
     def test_getobj_getlock_obj(self):
         arr1 = self.Array('i', range(10))
         lock1 = arr1.get_lock()