diff --git a/menu_block.admin.inc b/menu_block.admin.inc
index 98f3bbb77be7ab5dbab8ef6071823c6e69aa182a..d7bf10035dff3ac4bad3ae81d4bf031cc421b451 100644
--- a/menu_block.admin.inc
+++ b/menu_block.admin.inc
@@ -166,6 +166,8 @@ function menu_block_delete_submit($form, &$form_state) {
   variable_del("menu_block_{$delta}_depth");
   variable_del("menu_block_{$delta}_expanded");
   variable_del("menu_block_{$delta}_sort");
+  variable_del("menu_block_{$delta}_hide_siblings");
+  variable_del("menu_block_{$delta}_active_depth");
 
   db_delete('block')
     ->condition('module', 'menu_block')
@@ -423,6 +425,12 @@ function menu_block_configure_form($form, &$form_state) {
     '#default_value' => $config['sort'],
     '#description' => t('Sort each item in the active trail to the top of its level. When used on a deep or wide menu tree, the active menu item’s children will be easier to see when the page is reloaded.'),
   );
+  $form['hide_siblings'] = array(
+    '#type' => 'checkbox',
+    '#title' => t('<strong>Hide siblings</strong> of the active menu item’s trail.'),
+    '#default_value' => $config['hide_siblings'],
+    '#description' => t('If a menu item isn\'t in the active trail, don\'t show it.'),
+  );
   $form['parent_mlid'] = array(
     '#type' => 'select',
     '#title' => t('Fixed parent item'),
@@ -439,7 +447,7 @@ function menu_block_configure_form($form, &$form_state) {
   foreach (array('title_link', 'follow', 'follow_parent', 'expanded', 'sort', 'parent_mlid') as $key) {
     $form[$key]['#states']['visible'][':input[name=display_options]'] = array('value' => 'advanced');
   }
-  if ($config['title_link'] || $follow || $config['expanded'] || $config['sort'] || $config['parent_mlid']) {
+  if ($config['title_link'] || $follow || $config['expanded'] || $config['sort'] || $config['hide_siblings'] || $config['parent_mlid']) {
     $form['display_options']['#default_value'] = 'advanced';
   }
 
@@ -492,6 +500,7 @@ function _menu_block_block_save($delta = '', $edit = array()) {
       variable_set("menu_block_{$delta}_depth", $edit['depth']);
       variable_set("menu_block_{$delta}_expanded", $edit['expanded']);
       variable_set("menu_block_{$delta}_sort", $edit['sort']);
+      variable_set("menu_block_{$delta}_hide_siblings", $edit['hide_siblings']);
     }
   }
 }
diff --git a/menu_block.module b/menu_block.module
index 83cf0c98d475ddaf7ee1abd95cb384a026985131..c03ee69189f2e4ea8f42543aca46ac75722d3f75 100644
--- a/menu_block.module
+++ b/menu_block.module
@@ -192,6 +192,8 @@ function menu_block_get_config($delta = NULL) {
     'depth'       => 0,
     'expanded'    => 0,
     'sort'        => 0,
+    'hide_siblings' => 0,
+    'active_depth' => array(),
   );
 
   // Get the block configuration options.
@@ -216,6 +218,8 @@ function menu_block_get_config($delta = NULL) {
     $config['depth']       = variable_get("menu_block_{$delta}_depth",       $config['depth']);
     $config['expanded']    = variable_get("menu_block_{$delta}_expanded",    $config['expanded']);
     $config['sort']        = variable_get("menu_block_{$delta}_sort",        $config['sort']);
+    $config['hide_siblings'] = variable_get("menu_block_{$delta}_hide_siblings", $config['hide_siblings']);
+    $config['active_depth']   = variable_get("menu_block_{$delta}_active_depth",        $config['active_depth']);
     list($config['menu_name'], $config['parent_mlid']) = explode(':', variable_get("menu_block_{$delta}_parent", $config['menu_name'] . ':' . $config['parent_mlid']));
   }
 
@@ -352,6 +356,11 @@ function menu_tree_build($config) {
   if ($config['sort']) {
     menu_tree_sort_active_path($tree);
   }
+  
+  // When hiding siblings, level 1 is always in the active depth.
+  if ($config['hide_siblings']) {
+    $config['active_depth'][0] = 1;
+  }
 
   // Render the tree.
   $data = array();
@@ -643,6 +652,17 @@ function menu_block_tree_output(&$tree, $config = array()) {
   // Pull out just the menu items we are going to render so that we
   // get an accurate count for the first/last classes.
   foreach ($tree as $key => &$value) {
+    if ($config['hide_siblings']) {
+      // Build array of the active trails depth.
+      if ($tree[$key]['link']['in_active_trail'] && $tree[$key]['link']['depth'] > 1) {
+        $config['active_depth'][] = $tree[$key]['link']['depth'];
+      }
+      // Hide menu items on the same depth but that are not in the active trail ie. active trail siblings.
+      if ( in_array($tree[$key]['link']['depth'], $config['active_depth']) && $tree[$key]['link']['in_active_trail'] == FALSE ) {
+        $tree[$key]['link']['hidden'] = 1;
+      }
+    }
+    // Render all links that aren't hidden.
     if (!$tree[$key]['link']['hidden']) {
       $items[] = $tree[$key];
     }