diff --git a/moto/ec2/models.py b/moto/ec2/models.py
index 162338196..d40c21f57 100644
--- a/moto/ec2/models.py
+++ b/moto/ec2/models.py
@@ -107,7 +107,10 @@ class InstanceBackend(object):
         new_reservation = Reservation()
         new_reservation.id = random_reservation_id()
 
-        security_groups = [self.get_security_group_from_name(name) for name in security_group_names]
+        security_groups = [self.get_security_group_from_name(name)
+                           for name in security_group_names]
+        security_groups.extend(self.get_security_group_from_id(sg_id)
+                               for sg_id in kwargs.pop("security_group_ids", []))
         for index in range(count):
             new_instance = Instance(
                 image_id,
diff --git a/moto/ec2/responses/instances.py b/moto/ec2/responses/instances.py
index d3c2136fd..3b442eaea 100644
--- a/moto/ec2/responses/instances.py
+++ b/moto/ec2/responses/instances.py
@@ -9,7 +9,8 @@ from moto.ec2.exceptions import InvalidIdError
 
 class InstanceResponse(BaseResponse):
     def _get_multi_param(self, param_prefix):
-        return [value[0] for key, value in self.querystring.items() if key.startswith(param_prefix)]
+        return [value[0] for key, value in self.querystring.items()
+                if key.startswith(param_prefix + ".")]
 
     def describe_instances(self):
         instance_ids = instance_ids_from_querystring(self.querystring)
@@ -33,13 +34,14 @@ class InstanceResponse(BaseResponse):
         image_id = self.querystring.get('ImageId')[0]
         user_data = self.querystring.get('UserData')
         security_group_names = self._get_multi_param('SecurityGroup')
+        security_group_ids = self._get_multi_param('SecurityGroupId')
         instance_type = self.querystring.get("InstanceType", ["m1.small"])[0]
         subnet_id = self.querystring.get("SubnetId", [None])[0]
         key_name = self.querystring.get("KeyName", [None])[0]
         new_reservation = ec2_backend.add_instances(
             image_id, min_count, user_data, security_group_names,
             instance_type=instance_type, subnet_id=subnet_id,
-            key_name=key_name)
+            key_name=key_name, security_group_ids=security_group_ids)
         template = Template(EC2_RUN_INSTANCES)
         return template.render(reservation=new_reservation)
 
diff --git a/tests/test_ec2/test_instances.py b/tests/test_ec2/test_instances.py
index 3d52a76cc..9a0cd19be 100644
--- a/tests/test_ec2/test_instances.py
+++ b/tests/test_ec2/test_instances.py
@@ -173,11 +173,25 @@ def test_user_data_with_run_instance():
 
 
 @mock_ec2
-def test_run_instance_with_security_group():
+def test_run_instance_with_security_group_name():
     conn = boto.connect_ec2('the_key', 'the_secret')
     group = conn.create_security_group('group1', "some description")
 
-    reservation = conn.run_instances('ami-1234abcd', security_groups=['group1'])
+    reservation = conn.run_instances('ami-1234abcd',
+                                     security_groups=['group1'])
+    instance = reservation.instances[0]
+
+    instance.groups[0].id.should.equal(group.id)
+    instance.groups[0].name.should.equal("group1")
+
+
+@mock_ec2
+def test_run_instance_with_security_group_id():
+    conn = boto.connect_ec2('the_key', 'the_secret')
+    group = conn.create_security_group('group1', "some description")
+
+    reservation = conn.run_instances('ami-1234abcd',
+                                     security_group_ids=[group.id])
     instance = reservation.instances[0]
 
     instance.groups[0].id.should.equal(group.id)