diff --git a/django/core/exceptions.py b/django/core/exceptions.py
index f22f67c261..d9fc326cf2 100644
--- a/django/core/exceptions.py
+++ b/django/core/exceptions.py
@@ -4,6 +4,10 @@ class ObjectDoesNotExist(Exception):
     "The requested object does not exist"
     silent_variable_failure = True
 
+class MultipleObjectsReturned(Exception):
+    "The query returned multiple objects when only one was expected."
+    pass
+
 class SuspiciousOperation(Exception):
     "The user did something suspicious"
     pass
diff --git a/django/db/models/base.py b/django/db/models/base.py
index ae951fcaac..31bc907775 100644
--- a/django/db/models/base.py
+++ b/django/db/models/base.py
@@ -1,7 +1,7 @@
 import django.db.models.manipulators
 import django.db.models.manager
 from django.core import validators
-from django.core.exceptions import ObjectDoesNotExist
+from django.core.exceptions import ObjectDoesNotExist, MultipleObjectsReturned
 from django.db.models.fields import AutoField, ImageField, FieldDoesNotExist
 from django.db.models.fields.related import OneToOneRel, ManyToOneRel
 from django.db.models.query import delete_objects
@@ -35,6 +35,8 @@ class ModelBase(type):
         new_class = type.__new__(cls, name, bases, {'__module__': attrs.pop('__module__')})
         new_class.add_to_class('_meta', Options(attrs.pop('Meta', None)))
         new_class.add_to_class('DoesNotExist', types.ClassType('DoesNotExist', (ObjectDoesNotExist,), {}))
+        new_class.add_to_class('MultipleObjectsReturned',
+            types.ClassType('MultipleObjectsReturned', (MultipleObjectsReturned, ), {}))
 
         # Build complete list of parents
         for base in bases:
diff --git a/django/db/models/query.py b/django/db/models/query.py
index 4d0d295e97..0bc36f425a 100644
--- a/django/db/models/query.py
+++ b/django/db/models/query.py
@@ -261,7 +261,8 @@ class _QuerySet(object):
         obj_list = list(clone)
         if len(obj_list) < 1:
             raise self.model.DoesNotExist, "%s matching query does not exist." % self.model._meta.object_name
-        assert len(obj_list) == 1, "get() returned more than one %s -- it returned %s! Lookup parameters were %s" % (self.model._meta.object_name, len(obj_list), kwargs)
+        elif len(obj_list) > 1:
+            raise self.model.MultipleObjectsReturned, "get() returned more than one %s -- it returned %s! Lookup parameters were %s" % (self.model._meta.object_name, len(obj_list), kwargs)
         return obj_list[0]
 
     def create(self, **kwargs):
diff --git a/django/shortcuts/__init__.py b/django/shortcuts/__init__.py
index 611b997736..1cece7c7c0 100644
--- a/django/shortcuts/__init__.py
+++ b/django/shortcuts/__init__.py
@@ -38,7 +38,7 @@ def get_object_or_404(klass, *args, **kwargs):
     klass may be a Model, Manager, or QuerySet object. All other passed
     arguments and keyword arguments are used in the get() query.
 
-    Note: Like with get(), an AssertionError will be raised if more than one
+    Note: Like with get(), an MultipleObjectsReturned will be raised if more than one
     object is found.
     """
     queryset = _get_queryset(klass)
diff --git a/docs/shortcuts.txt b/docs/shortcuts.txt
index 6c55486b5f..f94babfecb 100644
--- a/docs/shortcuts.txt
+++ b/docs/shortcuts.txt
@@ -98,8 +98,8 @@ This example is equivalent to::
         except MyModel.DoesNotExist:
             raise Http404
 
-Note: As with ``get()``, an ``AssertionError`` will be raised if more than
-one object is found.
+Note: As with ``get()``, an ``MultipleObjectsReturned`` exception will be
+raised if more than one object is found.
 
 .. _get(): ../db-api/#get-kwargs
 
diff --git a/tests/modeltests/get_object_or_404/models.py b/tests/modeltests/get_object_or_404/models.py
index bd800317d3..d9f276b024 100644
--- a/tests/modeltests/get_object_or_404/models.py
+++ b/tests/modeltests/get_object_or_404/models.py
@@ -78,7 +78,7 @@ Http404: No Article matches the given query.
 >>> get_object_or_404(Author.objects.all())
 Traceback (most recent call last):
 ...
-AssertionError: get() returned more than one Author -- it returned ...! Lookup parameters were {}
+MultipleObjectsReturned: get() returned more than one Author -- it returned ...! Lookup parameters were {}
 
 # Using an EmptyQuerySet raises a Http404 error.
 >>> get_object_or_404(Article.objects.none(), title__contains="Run")