diff --git a/Scripts/Editor/NodeEditorAction.cs b/Scripts/Editor/NodeEditorAction.cs
index 1258983..511f5d3 100644
--- a/Scripts/Editor/NodeEditorAction.cs
+++ b/Scripts/Editor/NodeEditorAction.cs
@@ -420,7 +420,7 @@ namespace XNodeEditor {
             //Get node position
             Vector2 nodePos = GridToWindowPosition(node.position);
             float width = 200;
-            if (nodeWidths.ContainsKey(node)) width = nodeWidths[node];
+            if (nodeSizes.ContainsKey(node)) width = nodeSizes[node].x;
             Rect windowRect = new Rect(nodePos, new Vector2(width / zoom, 30 / zoom));
             return windowRect.Contains(mousePos);
         }
diff --git a/Scripts/Editor/NodeEditorGUI.cs b/Scripts/Editor/NodeEditorGUI.cs
index a1e8fd3..c83f544 100644
--- a/Scripts/Editor/NodeEditorGUI.cs
+++ b/Scripts/Editor/NodeEditorGUI.cs
@@ -8,6 +8,7 @@ namespace XNodeEditor {
     public partial class NodeEditorWindow {
         public NodeGraphEditor graphEditor;
         private List<UnityEngine.Object> selectionCache;
+        private List<XNode.Node> culledNodes;
 
         private void OnGUI() {
             Event e = Event.current;
@@ -280,10 +281,6 @@ namespace XNodeEditor {
             if (e.type == EventType.Layout) {
                 selectionCache = new List<UnityEngine.Object>(Selection.objects);
             }
-            if (e.type == EventType.Repaint) {
-                portConnectionPoints.Clear();
-                nodeWidths.Clear();
-            }
 
             //Active node is hashed before and after node GUI to detect changes
             int nodeHash = 0;
@@ -313,6 +310,8 @@ namespace XNodeEditor {
 
             //Save guiColor so we can revert it
             Color guiColor = GUI.color;
+
+            if (e.type == EventType.Layout) culledNodes = new List<XNode.Node>();
             for (int n = 0; n < graph.nodes.Count; n++) {
                 // Skip null nodes. The user could be in the process of renaming scripts, so removing them at this point is not advisable.
                 if (graph.nodes[n] == null) continue;
@@ -320,6 +319,17 @@ namespace XNodeEditor {
                 XNode.Node node = graph.nodes[n];
 
                 NodeEditor nodeEditor = NodeEditor.GetEditor(node);
+
+                // Culling
+                if (e.type == EventType.Layout) {
+                    // Cull unselected nodes outside view
+                    if (!Selection.Contains(node) && ShouldBeCulled(nodeEditor)) {
+                        culledNodes.Add(node);
+                        continue;
+                    }
+                } else if (culledNodes.Contains(node)) continue;
+
+                Debug.Log("Draw " + n);
                 NodeEditor.portPositions = new Dictionary<XNode.NodePort, Vector2>();
 
                 //Get node position
@@ -358,18 +368,23 @@ namespace XNodeEditor {
                     if (NodeEditor.onUpdateNode != null) NodeEditor.onUpdateNode(node);
                 }
 
+                GUILayout.EndVertical();
+
+                //Cache data about the node for next frame
                 if (e.type == EventType.Repaint) {
-                    nodeWidths.Add(node, nodeEditor.GetWidth());
+                    Vector2 size = GUILayoutUtility.GetLastRect().size;
+                    if (nodeSizes.ContainsKey(node)) nodeSizes[node] = size;
+                    else nodeSizes.Add(node, size);
 
                     foreach (var kvp in NodeEditor.portPositions) {
                         Vector2 portHandlePos = kvp.Value;
                         portHandlePos += node.position;
                         Rect rect = new Rect(portHandlePos.x - 8, portHandlePos.y - 8, 16, 16);
-                        portConnectionPoints.Add(kvp.Key, rect);
+                        if (portConnectionPoints.ContainsKey(kvp.Key)) portConnectionPoints[kvp.Key] = rect;
+                        else portConnectionPoints.Add(kvp.Key, rect);
                     }
                 }
 
-                GUILayout.EndVertical();
                 if (selected) GUILayout.EndVertical();
 
                 if (e.type != EventType.Layout) {
@@ -414,6 +429,19 @@ namespace XNodeEditor {
             }
         }
 
+        /// <summary> Returns true if outside window area </summary>
+        private bool ShouldBeCulled(XNodeEditor.NodeEditor nodeEditor) {
+            Vector2 nodePos = GridToWindowPositionNoClipped(nodeEditor.target.position);
+            if (nodePos.x / _zoom > position.width) return true; // Right
+            else if (nodePos.y / _zoom > position.height) return true; // Bottom
+            else if (nodeSizes.ContainsKey(nodeEditor.target)) {
+                Vector2 size = nodeSizes[nodeEditor.target];
+                if (nodePos.x + size.x < 0) return true; // Left
+                else if (nodePos.y + size.y < 0) return true; // Top
+            }
+            return false;
+        }
+
         private void DrawTooltip() {
             if (hoveredPort != null) {
                 Type type = hoveredPort.ValueType;
diff --git a/Scripts/Editor/NodeEditorWindow.cs b/Scripts/Editor/NodeEditorWindow.cs
index a5cbf3f..7fdc49d 100644
--- a/Scripts/Editor/NodeEditorWindow.cs
+++ b/Scripts/Editor/NodeEditorWindow.cs
@@ -11,8 +11,8 @@ namespace XNodeEditor {
         /// <summary> Stores node positions for all nodePorts. </summary>
         public Dictionary<XNode.NodePort, Rect> portConnectionPoints { get { return _portConnectionPoints; } }
         private Dictionary<XNode.NodePort, Rect> _portConnectionPoints = new Dictionary<XNode.NodePort, Rect>();
-        public Dictionary<XNode.Node, float> nodeWidths { get { return _nodeWidths; } }
-        private Dictionary<XNode.Node, float> _nodeWidths = new Dictionary<XNode.Node, float>();
+        public Dictionary<XNode.Node, Vector2> nodeSizes { get { return _nodeSizes; } }
+        private Dictionary<XNode.Node, Vector2> _nodeSizes = new Dictionary<XNode.Node, Vector2>();
         public XNode.NodeGraph graph;
         public Vector2 panOffset { get { return _panOffset; } set { _panOffset = value; Repaint(); } }
         private Vector2 _panOffset;