diff --git a/dist/vis.js b/dist/vis.js
index 49849530..e48df784 100644
--- a/dist/vis.js
+++ b/dist/vis.js
@@ -12131,7 +12131,9 @@ var HierarchicalLayoutMixin = {
    */
   _setupHierarchicalLayout : function() {
     if (this.constants.hierarchicalLayout.enabled == true) {
-
+      if (this.constants.hierarchicalLayout.direction == "RL" || this.constants.hierarchicalLayout.direction == "DU") {
+        this.constants.hierarchicalLayout.levelSeparation *= -1;
+      }
       // get the size of the largest hubs and check if the user has defined a level for a node.
       var hubsize = 0;
       var node, nodeId;
@@ -12195,10 +12197,21 @@ var HierarchicalLayoutMixin = {
     for (nodeId in distribution[0].nodes) {
       if (distribution[0].nodes.hasOwnProperty(nodeId)) {
         node = distribution[0].nodes[nodeId];
-        if (node.xFixed) {
-          node.x = distribution[0].minPos;
-          distribution[0].minPos += distribution[0].nodeSpacing;
-          node.xFixed = false;
+        if (this.constants.hierarchicalLayout.direction == "UD" || this.constants.hierarchicalLayout.direction == "DU") {
+          if (node.xFixed) {
+            node.x = distribution[0].minPos;
+            node.xFixed = false;
+
+            distribution[0].minPos += distribution[0].nodeSpacing;
+          }
+        }
+        else {
+          if (node.yFixed) {
+            node.y = distribution[0].minPos;
+            node.yFixed = false;
+
+            distribution[0].minPos += distribution[0].nodeSpacing;
+          }
         }
         this._placeBranchNodes(node.edges,node.id,distribution,node.level);
       }
@@ -12226,7 +12239,12 @@ var HierarchicalLayoutMixin = {
         node = this.nodes[nodeId];
         node.xFixed = true;
         node.yFixed = true;
-        node.y = this.constants.hierarchicalLayout.levelSeparation*node.level;
+        if (this.constants.hierarchicalLayout.direction == "UD" || this.constants.hierarchicalLayout.direction == "DU") {
+          node.y = this.constants.hierarchicalLayout.levelSeparation*node.level;
+        }
+        else {
+          node.x = this.constants.hierarchicalLayout.levelSeparation*node.level;
+        }
         if (!distribution.hasOwnProperty(node.level)) {
           distribution[node.level] = {amount: 0, nodes: {}, minPos:0, nodeSpacing:0};
         }
@@ -12329,9 +12347,23 @@ var HierarchicalLayoutMixin = {
       }
 
       // if a node is conneceted to another node on the same level (or higher (means lower level))!, this is not handled here.
-      if (childNode.xFixed && childNode.level > parentLevel) {
-        childNode.xFixed = false;
-        childNode.x = distribution[childNode.level].minPos;
+      var nodeMoved = false;
+      if (this.constants.hierarchicalLayout.direction == "UD" || this.constants.hierarchicalLayout.direction == "DU") {
+        if (childNode.xFixed && childNode.level > parentLevel) {
+          childNode.xFixed = false;
+          childNode.x = distribution[childNode.level].minPos;
+          nodeMoved = true;
+        }
+      }
+      else {
+        if (childNode.yFixed && childNode.level > parentLevel) {
+          childNode.yFixed = false;
+          childNode.y = distribution[childNode.level].minPos;
+          nodeMoved = true;
+        }
+      }
+
+      if (nodeMoved == true) {
         distribution[childNode.level].minPos += distribution[childNode.level].nodeSpacing;
         if (childNode.edges.length > 1) {
           this._placeBranchNodes(childNode.edges,childNode.id,distribution,childNode.level);
@@ -15606,7 +15638,8 @@ function Graph (container, data, options) {
     hierarchicalLayout: {
       enabled:false,
       levelSeparation: 150,
-      nodeSpacing: 100
+      nodeSpacing: 100,
+      direction: "UD"   // UD, DU, LR, RL
     },
     smoothCurves: true,
     maxVelocity:  10,
@@ -15716,7 +15749,6 @@ function Graph (container, data, options) {
     }
   }
 
-
   // if clustering is disabled, the simulation will have started in the setData function
   if (this.constants.clustering.enabled) {
     this.startWithClustering();
@@ -16389,7 +16421,6 @@ Graph.prototype._onTap = function (event) {
 Graph.prototype._onDoubleTap = function (event) {
   var pointer = this._getPointer(event.gesture.center);
   this._handleDoubleTap(pointer);
-
 };
 
 
@@ -17404,12 +17435,6 @@ Graph.prototype._initializeMixinLoaders = function () {
 
 
 
-
-
-
-
-
-
 /**
  * vis.js module exports
  */
diff --git a/docs/graph.html b/docs/graph.html
index 2ba9951c..407977cb 100644
--- a/docs/graph.html
+++ b/docs/graph.html
@@ -1663,12 +1663,20 @@ var options: {
     hierarchicalLayout: true
 }
 
-// advanced configuration for keyboard controls
+// advanced configuration for hierarchical layout
 var options: {
     hierarchicalLayout: {
       enabled:false,
       levelSeparation: 150,
-      nodeSpacing: 100
+      nodeSpacing: 100,
+      direction: "UD"
+    }
+}
+// partial configuration automatically sets enabled to true
+var options: {
+    hierarchicalLayout: {
+      nodeSpacing: 100,
+      direction: "UD"
     }
 }
 </pre>
@@ -1692,13 +1700,20 @@ var options: {
         <td>levelSeparation</td>
         <td>Number</td>
         <td>150</td>
-        <td>This defines the space between levels (in the Y-direction).</td>
+        <td>This defines the space between levels (in the Y-direction, considering UP-DOWN direction).</td>
     </tr>
     <tr>
         <td>nodeSpacing</td>
         <td>Number</td>
         <td>100</td>
-        <td>This defines the space between nodes in the same level (in the X-direction).</td>
+        <td>This defines the space between nodes in the same level (in the X-direction, considering UP-DOWN direction).</td>
+    </tr>
+    <tr>
+        <td>direction</td>
+        <td>String</td>
+        <td>UD</td>
+        <td>This defines the direction the graph is drawn in. The supported directions are: Up-Down (UD), Down-Up (DU), Left-Right (LR) and Right-Left (RL).
+        These need to be supplied by the acronyms in parentheses.</td>
     </tr>
 </table>
 <h2 id="Methods">Methods</h2>
diff --git a/examples/graph/23_hierarchical_layout.html b/examples/graph/23_hierarchical_layout.html
index 2545dbbc..508c9de6 100644
--- a/examples/graph/23_hierarchical_layout.html
+++ b/examples/graph/23_hierarchical_layout.html
@@ -21,6 +21,8 @@
     var edges = null;
     var graph = null;
 
+
+
     function draw() {
       nodes = [];
       edges = [];
@@ -75,12 +77,14 @@
         nodes: nodes,
         edges: edges
       };
-
+    var directionInput = document.getElementById("direction");
     var options = {
         edges: {
         },
         stabilize: false,
-        hierarchicalLayout:true
+        hierarchicalLayout: {
+            direction: directionInput.value
+        }
     };
       graph = new vis.Graph(container, data, options);
 
@@ -89,6 +93,7 @@
         document.getElementById('selection').innerHTML = 'Selection: ' + params.nodes;
       });
     }
+
   </script>
 </head>
 
@@ -104,6 +109,35 @@
   <input id="nodeCount" type="text" value="25" style="width: 50px;">
   <input type="submit" value="Go">
 </form>
+<input type="button" id="btn-UD" value="Up-Down">
+<input type="button" id="btn-DU" value="Down-Up">
+<input type="button" id="btn-LR" value="Left-Right">
+<input type="button" id="btn-RL" value="Right-Left">
+<input type="hidden" id='direction' value="UD">
+
+<script language="javascript">
+    var directionInput = document.getElementById("direction");
+    var btnUD = document.getElementById("btn-UD");
+    btnUD.onclick = function() {
+        directionInput.value = "UD";
+        draw();
+    }
+    var btnDU = document.getElementById("btn-DU");
+    btnDU.onclick = function() {
+        directionInput.value = "DU";
+        draw();
+    };
+    var btnLR = document.getElementById("btn-LR");
+    btnLR.onclick = function() {
+        directionInput.value = "LR";
+        draw();
+    };
+    var btnRL = document.getElementById("btn-RL");
+    btnRL.onclick = function() {
+        directionInput.value = "RL";
+        draw();
+    };
+</script>
 <br>
 
 <div id="mygraph"></div>
diff --git a/src/graph/Graph.js b/src/graph/Graph.js
index cb51a28a..8e13055c 100644
--- a/src/graph/Graph.js
+++ b/src/graph/Graph.js
@@ -138,7 +138,8 @@ function Graph (container, data, options) {
     hierarchicalLayout: {
       enabled:false,
       levelSeparation: 150,
-      nodeSpacing: 100
+      nodeSpacing: 100,
+      direction: "UD"   // UD, DU, LR, RL
     },
     smoothCurves: true,
     maxVelocity:  10,
@@ -248,7 +249,6 @@ function Graph (container, data, options) {
     }
   }
 
-
   // if clustering is disabled, the simulation will have started in the setData function
   if (this.constants.clustering.enabled) {
     this.startWithClustering();
@@ -921,7 +921,6 @@ Graph.prototype._onTap = function (event) {
 Graph.prototype._onDoubleTap = function (event) {
   var pointer = this._getPointer(event.gesture.center);
   this._handleDoubleTap(pointer);
-
 };
 
 
@@ -1935,9 +1934,3 @@ Graph.prototype._initializeMixinLoaders = function () {
 
 
 
-
-
-
-
-
-
diff --git a/src/graph/graphMixins/HierarchicalLayoutMixin.js b/src/graph/graphMixins/HierarchicalLayoutMixin.js
index 922e9757..63ebf556 100644
--- a/src/graph/graphMixins/HierarchicalLayoutMixin.js
+++ b/src/graph/graphMixins/HierarchicalLayoutMixin.js
@@ -9,7 +9,9 @@ var HierarchicalLayoutMixin = {
    */
   _setupHierarchicalLayout : function() {
     if (this.constants.hierarchicalLayout.enabled == true) {
-
+      if (this.constants.hierarchicalLayout.direction == "RL" || this.constants.hierarchicalLayout.direction == "DU") {
+        this.constants.hierarchicalLayout.levelSeparation *= -1;
+      }
       // get the size of the largest hubs and check if the user has defined a level for a node.
       var hubsize = 0;
       var node, nodeId;
@@ -73,10 +75,21 @@ var HierarchicalLayoutMixin = {
     for (nodeId in distribution[0].nodes) {
       if (distribution[0].nodes.hasOwnProperty(nodeId)) {
         node = distribution[0].nodes[nodeId];
-        if (node.xFixed) {
-          node.x = distribution[0].minPos;
-          distribution[0].minPos += distribution[0].nodeSpacing;
-          node.xFixed = false;
+        if (this.constants.hierarchicalLayout.direction == "UD" || this.constants.hierarchicalLayout.direction == "DU") {
+          if (node.xFixed) {
+            node.x = distribution[0].minPos;
+            node.xFixed = false;
+
+            distribution[0].minPos += distribution[0].nodeSpacing;
+          }
+        }
+        else {
+          if (node.yFixed) {
+            node.y = distribution[0].minPos;
+            node.yFixed = false;
+
+            distribution[0].minPos += distribution[0].nodeSpacing;
+          }
         }
         this._placeBranchNodes(node.edges,node.id,distribution,node.level);
       }
@@ -104,7 +117,12 @@ var HierarchicalLayoutMixin = {
         node = this.nodes[nodeId];
         node.xFixed = true;
         node.yFixed = true;
-        node.y = this.constants.hierarchicalLayout.levelSeparation*node.level;
+        if (this.constants.hierarchicalLayout.direction == "UD" || this.constants.hierarchicalLayout.direction == "DU") {
+          node.y = this.constants.hierarchicalLayout.levelSeparation*node.level;
+        }
+        else {
+          node.x = this.constants.hierarchicalLayout.levelSeparation*node.level;
+        }
         if (!distribution.hasOwnProperty(node.level)) {
           distribution[node.level] = {amount: 0, nodes: {}, minPos:0, nodeSpacing:0};
         }
@@ -207,9 +225,23 @@ var HierarchicalLayoutMixin = {
       }
 
       // if a node is conneceted to another node on the same level (or higher (means lower level))!, this is not handled here.
-      if (childNode.xFixed && childNode.level > parentLevel) {
-        childNode.xFixed = false;
-        childNode.x = distribution[childNode.level].minPos;
+      var nodeMoved = false;
+      if (this.constants.hierarchicalLayout.direction == "UD" || this.constants.hierarchicalLayout.direction == "DU") {
+        if (childNode.xFixed && childNode.level > parentLevel) {
+          childNode.xFixed = false;
+          childNode.x = distribution[childNode.level].minPos;
+          nodeMoved = true;
+        }
+      }
+      else {
+        if (childNode.yFixed && childNode.level > parentLevel) {
+          childNode.yFixed = false;
+          childNode.y = distribution[childNode.level].minPos;
+          nodeMoved = true;
+        }
+      }
+
+      if (nodeMoved == true) {
         distribution[childNode.level].minPos += distribution[childNode.level].nodeSpacing;
         if (childNode.edges.length > 1) {
           this._placeBranchNodes(childNode.edges,childNode.id,distribution,childNode.level);