diff --git a/haskell-neo4j-client.cabal b/haskell-neo4j-client.cabal
--- a/haskell-neo4j-client.cabal
+++ b/haskell-neo4j-client.cabal
@@ -1,5 +1,5 @@
 name:                haskell-neo4j-client
-version:             0.3.0.7
+version:             0.3.0.8
 synopsis:            A Haskell neo4j client
 description:         
     Library to interact with Neo4j databases. 
diff --git a/src/Database/Neo4j.hs b/src/Database/Neo4j.hs
--- a/src/Database/Neo4j.hs
+++ b/src/Database/Neo4j.hs
@@ -24,7 +24,7 @@
         setProperty, deleteProperties, deleteProperty, 
     -- * Managing nodes
     Node, getNodeProperties, createNode, getNode, deleteNode, nodeId, nodePath, runNodeIdentifier, NodeIdentifier(..),
-    NodePath(..),
+         NodePath(..),
     -- * Managing relationships
     Relationship, Direction(..), RelationshipType, createRelationship, getRelationship, deleteRelationship,
         getRelationships, relId, relPath, allRelationshipTypes, getRelProperties, getRelType, runRelIdentifier,
diff --git a/src/Database/Neo4j/Graph.hs b/src/Database/Neo4j/Graph.hs
--- a/src/Database/Neo4j/Graph.hs
+++ b/src/Database/Neo4j/Graph.hs
@@ -232,18 +232,19 @@
 
 -- | Filter the nodes of a graph
 nodeFilter :: (Node -> Bool) -> Graph -> Graph
-nodeFilter f g = foldl (\gacc n -> if f n then deleteNode n gacc else gacc) g (M.elems $ nodes g)
+nodeFilter f g = foldl (\gacc n -> if f n then gacc else deleteNode n gacc) g (M.elems $ nodes g)
 
 -- | Filter the relationships of a graph
 relationshipFilter :: (Relationship -> Bool) -> Graph -> Graph
-relationshipFilter f g = foldl (\gacc r -> if f r then deleteRelationship r gacc else gacc) g (M.elems $ rels g)
+relationshipFilter f g = foldl (\gacc r -> if f r then gacc else deleteRelationship r gacc) g (M.elems $ rels g)
 
 -- | Add two graphs resulting in a graph with all the nodes, labels and relationships of both
 -- | If a node/entity is present in both the second one will be chosen
 union :: Graph -> Graph -> Graph
-union ga gb = addRels ga (addNodes ga gb)
-    where addRels g1 g2 = foldl (flip addRelationship) g1 (M.elems $ rels g2)
-          addNodes g1 g2 = foldl (flip addNode) g1 (M.elems $ nodes g2)
+union ga gb = addLabels (addRels (addNodes ga gb) gb) gb
+    where addRels g1 g2 = foldl (\gacc r -> addRelationship r gacc) g1 (getRelationships g2)
+          addNodes g1 g2 = foldl (flip addNode) g1 (getNodes g2)
+          addLabels g1 g2 = foldl (\gacc n -> setNodeLabels n (HS.toList $ getNodeLabels n g2) gacc) g1 (getNodes g2)
 
 -- | Remove the nodes and relationships in the first graph that appear in the second
 difference :: Graph -> Graph -> Graph
diff --git a/tests/IntegrationTests.hs b/tests/IntegrationTests.hs
--- a/tests/IntegrationTests.hs
+++ b/tests/IntegrationTests.hs
@@ -2,7 +2,7 @@
 {-# LANGUAGE FlexibleInstances, TemplateHaskell #-}
 module Main where
 
-import Control.Monad (void)
+import Control.Monad (void, join)
 import Control.Monad.IO.Class (MonadIO, liftIO)
 import Data.Monoid (Monoid, mappend)
 import Data.Int (Int64)
@@ -77,6 +77,16 @@
 host :: Hostname
 host = "localhost"
 
+someOtherProperties :: Properties
+someOtherProperties = M.fromList ["hola" |: ("adeu" :: T.Text), "proparray" |: ["a" :: T.Text, "", "adeu"]]
+
+anotherProperties :: Properties
+anotherProperties = M.empty
+
+myRelType :: T.Text
+myRelType = "MYREL"
+
+
 -- | Test connecting to a non-existing server
 case_NoConnection :: Assertion
 case_NoConnection = assertException expException $ withConnection "localhost" 77 $ createNode someProperties
@@ -299,15 +309,6 @@
         return ()
     where valName = "noproperty"
 
-someOtherProperties :: Properties
-someOtherProperties = M.fromList ["hola" |: ("adeu" :: T.Text), "proparray" |: ["a" :: T.Text, "", "adeu"]]
-
-anotherProperties :: Properties
-anotherProperties = M.empty
-
-myRelType :: T.Text
-myRelType = "MYREL"
-
 setupRelTests :: Neo4j (Node, Node, Relationship)
 setupRelTests = do
     nodeFrom <- createNode anotherProperties
@@ -1524,3 +1525,69 @@
             TC.commit
             return result
     where expException = TransactionEndedExc
+
+-- | Test graph union op
+case_graphUnion :: Assertion
+case_graphUnion = withConnection host port $ do
+                g <- B.runBatch $ do
+                    n1 <- B.createNode someProperties
+                    n2 <- B.createNode anotherProperties
+                    void $ B.addLabels ["a"] n1
+                    _ <- B.createRelationship "type1" someOtherProperties n1 n2
+                    B.createRelationship "type2" someProperties n2 n1
+                g2 <- B.runBatch $ do
+                    n1 <- B.createNode someOtherProperties
+                    n2 <- B.createNode anotherProperties
+                    void $ B.addLabels ["b"] n1
+                    _ <- B.createRelationship "type1" someOtherProperties n1 n2
+                    B.createRelationship "type2" someProperties n2 n1
+                let g3 = g `G.union` g2
+                let g4 = G.addRelationship (head $ G.getRelationships g) g2
+                neo4jEqual 3 (length $ G.getRelationships g4)
+                neo4jEqual 4 (length $ G.getNodes g3)
+                neo4jEqual 4 (length $ G.getRelationships g3)
+                neo4jBool $ someOtherProperties `elem` map getRelProperties (G.getRelationships g3)
+                neo4jBool $ someProperties `elem` map getRelProperties (G.getRelationships g3)
+                neo4jBool $ someOtherProperties `elem` map getNodeProperties (G.getNodes g3)
+                neo4jBool $ someProperties `elem` map getNodeProperties (G.getNodes g3)
+                neo4jBool $ "type1" `elem` map getRelType (G.getRelationships g3)
+                neo4jBool $ "type2" `elem` map getRelType (G.getRelationships g3)
+                neo4jBool $ "a" `elem` (join $ map (HS.toList . (flip G.getNodeLabels g3)) (G.getNodes g3))
+                neo4jBool $ "b" `elem` (join $ map (HS.toList . (flip G.getNodeLabels g3)) (G.getNodes g3))
+                mapM_ deleteRelationship (G.getRelationships g3)
+                mapM_ deleteNode (G.getNodes g3)
+
+-- | Test graph difference op
+case_graphDifference :: Assertion
+case_graphDifference = withConnection host port $ do
+                g <- B.runBatch $ do
+                    n1 <- B.createNode someProperties
+                    n2 <- B.createNode anotherProperties
+                    void $ B.addLabels ["a"] n1
+                    _ <- B.createRelationship "type1" someOtherProperties n1 n2
+                    B.createRelationship "type2" someProperties n2 n1
+                let g2 = g `G.difference` g
+                neo4jEqual 0 (length $ G.getRelationships g2)
+                neo4jEqual 0 (length $ G.getNodes g2)
+                let subGraph = G.deleteNode (head $ G.getNodes g) g
+                let g3 = g `G.difference` (G.deleteRelationship (head $ G.getRelationships subGraph) subGraph)
+                neo4jEqual 1 (length $ G.getRelationships g3)
+                neo4jEqual 1 (length $ G.getNodes g3)
+
+-- | Test graph intersection op
+case_graphIntersection :: Assertion
+case_graphIntersection = withConnection host port $ do
+                g <- B.runBatch $ do
+                    n1 <- B.createNode someProperties
+                    n2 <- B.createNode anotherProperties
+                    void $ B.addLabels ["a"] n1
+                    _ <- B.createRelationship "type1" someOtherProperties n1 n2
+                    B.createRelationship "type2" someProperties n2 n1
+                g2 <- B.runBatch $ do
+                    B.createNode someProperties
+                let g3 = G.addNode (head $ G.getNodes g) g2
+                let g4 = g `G.intersection` (G.addRelationship (head $ G.getRelationships g) g3)
+                neo4jEqual 1 (length $ G.getRelationships g4)
+                neo4jEqual 1 (length $ G.getNodes g4)
+                neo4jEqual (head $ G.getRelationships g) (head $ G.getRelationships g4)
+                neo4jEqual (head $ G.getNodes g) (head $ G.getNodes g4)