diff --git a/rhodecode/templates/changeset/changeset_file_comment.html b/rhodecode/templates/changeset/changeset_file_comment.html
--- a/rhodecode/templates/changeset/changeset_file_comment.html
+++ b/rhodecode/templates/changeset/changeset_file_comment.html
@@ -37,7 +37,7 @@
 
 <%def name="comment_inline_form(changeset)">
 <div id='comment-inline-form-template' style="display:none">
-  <div class="comment-inline-form">
+  <div class="comment-inline-form ac">
   %if c.rhodecode_user.username != 'default':
     <div class="overlay"><div class="overlay-text">${_('Submitting...')}</div></div>
       ${h.form(h.url('changeset_comment', repo_name=c.repo_name, revision=changeset.raw_id),class_='inline-form')}
@@ -45,8 +45,10 @@
           <div class="comment-help">${_('Commenting on line {1}.')}
           ${(_('Comments parsed using %s syntax with %s support.') % (('<a href="%s">RST</a>' % h.url('rst_help')),
           	'<span style="color:#003367" class="tooltip" title="%s">@mention</span>' %
-          	_('Use @username inside this text to send notification to this RhodeCode user')))|n}</div>
-          <textarea id="text_{1}" name="text"></textarea>
+          	_('Use @username inside this text to send notification to this RhodeCode user')))|n}
+          </div>
+            <div class="mentions-container" id="mentions_container_{1}"></div>
+            <textarea id="text_{1}" name="text" class="yui-ac-input"></textarea>
       </div>
       <div class="comment-button">
       <input type="hidden" name="f_path" value="{0}">
@@ -100,7 +102,7 @@
         </div>
     %endfor
     %if c.rhodecode_user.username != 'default':
-    <div class="comment-form">
+    <div class="comment-form ac">
         ${h.form(h.url('changeset_comment', repo_name=c.repo_name, revision=changeset.raw_id))}
         <strong>${_('Leave a comment')}</strong>
         <div class="clearfix">
@@ -119,7 +121,8 @@
                     </div>                    
                 %endfor
             </div>                 
-            ${h.textarea('text')}
+            <div class="mentions-container" id="mentions_container"></div>
+             ${h.textarea('text')}
         </div>
         <div class="comment-button">
         ${h.submit('save', _('Comment'), class_='ui-button')}
@@ -128,4 +131,9 @@
     </div>
     %endif
 </div>
+<script>
+YUE.onDOMReady(function () {
+   MentionsAutoComplete('text', 'mentions_container', _USERS_AC_DATA, _GROUPS_AC_DATA);
+});
+</script>
 </%def>