diff --git a/moto/ec2/models.py b/moto/ec2/models.py
index 4b143eeab..e7e8a1dd8 100755
--- a/moto/ec2/models.py
+++ b/moto/ec2/models.py
@@ -1836,8 +1836,8 @@ class EBSBackend(object):
     def describe_snapshots(self, snapshot_ids=None, filters=None):
         matches = self.snapshots.values()
         if snapshot_ids:
-            matches = [vol for vol in matches
-                       if vol.id in snapshot_ids]
+            matches = [snap for snap in matches
+                       if snap.id in snapshot_ids]
             if len(snapshot_ids) > len(matches):
                 unknown_ids = set(snapshot_ids) - set(matches)
                 raise InvalidSnapshotIdError(unknown_ids)
@@ -1962,12 +1962,16 @@ class VPCBackend(object):
         return self.vpcs.get(vpc_id)
 
     def get_all_vpcs(self, vpc_ids=None, filters=None):
+        matches = self.vpcs.values()
         if vpc_ids:
-            vpcs = [vpc for vpc in self.vpcs.values() if vpc.id in vpc_ids]
-        else:
-            vpcs = self.vpcs.values()
-
-        return generic_filter(filters, vpcs)
+            matches = [vpc for vpc in matches
+                       if vpc.id in vpc_ids]
+            if len(vpc_ids) > len(matches):
+                unknown_ids = set(vpc_ids) - set(matches)
+                raise InvalidVPCIdError(unknown_ids)
+        if filters:
+            matches = generic_filter(filters, matches)
+        return matches
 
     def delete_vpc(self, vpc_id):
         # Delete route table if only main route table remains.
@@ -2204,16 +2208,19 @@ class SubnetBackend(object):
         return subnet
 
     def get_all_subnets(self, subnet_ids=None, filters=None):
-        subnets = []
+        # Extract a list of all subnets
+        matches = itertools.chain(*[x.values()
+                                    for x in self.subnets.values()])
         if subnet_ids:
-            for subnet_id in subnet_ids:
-                for items in self.subnets.values():
-                    if subnet_id in items:
-                        subnets.append(items[subnet_id])
-        else:
-            for items in self.subnets.values():
-                subnets.extend(items.values())
-        return generic_filter(filters, subnets)
+            matches = [sn for sn in matches
+                       if sn.id in subnet_ids]
+            if len(subnet_ids) > len(matches):
+                unknown_ids = set(subnet_ids) - set(matches)
+                raise InvalidSubnetIdError(unknown_ids)
+        if filters:
+            matches = generic_filter(filters, matches)
+
+        return matches
 
     def delete_subnet(self, subnet_id):
         for subnets in self.subnets.values():
diff --git a/tests/test_ec2/test_subnets.py b/tests/test_ec2/test_subnets.py
index 38565a28f..99e6d45d8 100644
--- a/tests/test_ec2/test_subnets.py
+++ b/tests/test_ec2/test_subnets.py
@@ -158,6 +158,32 @@ def test_modify_subnet_attribute_validation():
             SubnetId=subnet.id, MapPublicIpOnLaunch={'Value': 'invalid'})
 
 
+@mock_ec2_deprecated
+def test_subnet_get_by_id():
+    ec2 = boto.ec2.connect_to_region('us-west-1')
+    conn = boto.vpc.connect_to_region('us-west-1')
+    vpcA = conn.create_vpc("10.0.0.0/16")
+    subnetA = conn.create_subnet(
+        vpcA.id, "10.0.0.0/24", availability_zone='us-west-1a')
+    vpcB = conn.create_vpc("10.0.0.0/16")
+    subnetB1 = conn.create_subnet(
+        vpcB.id, "10.0.0.0/24", availability_zone='us-west-1a')
+    subnetB2 = conn.create_subnet(
+        vpcB.id, "10.0.1.0/24", availability_zone='us-west-1b')
+
+    subnets_by_id = conn.get_all_subnets(subnet_ids=[subnetA.id, subnetB1.id])
+    subnets_by_id.should.have.length_of(2)
+    subnets_by_id = tuple(map(lambda s: s.id, subnets_by_id))
+    subnetA.id.should.be.within(subnets_by_id)
+    subnetB1.id.should.be.within(subnets_by_id)
+
+    with assert_raises(EC2ResponseError) as cm:
+        conn.get_all_subnets(subnet_ids=['subnet-does_not_exist'])
+    cm.exception.code.should.equal('InvalidSubnetID.NotFound')
+    cm.exception.status.should.equal(400)
+    cm.exception.request_id.should_not.be.none
+
+
 @mock_ec2_deprecated
 def test_get_subnets_filtering():
     ec2 = boto.ec2.connect_to_region('us-west-1')
diff --git a/tests/test_ec2/test_vpcs.py b/tests/test_ec2/test_vpcs.py
index 904603f6d..fc0a93cbb 100644
--- a/tests/test_ec2/test_vpcs.py
+++ b/tests/test_ec2/test_vpcs.py
@@ -113,6 +113,12 @@ def test_vpc_get_by_id():
     vpc1.id.should.be.within(vpc_ids)
     vpc2.id.should.be.within(vpc_ids)
 
+    with assert_raises(EC2ResponseError) as cm:
+        conn.get_all_vpcs(vpc_ids=['vpc-does_not_exist'])
+    cm.exception.code.should.equal('InvalidVpcID.NotFound')
+    cm.exception.status.should.equal(400)
+    cm.exception.request_id.should_not.be.none
+
 
 @mock_ec2_deprecated
 def test_vpc_get_by_cidr_block():