<link href="//maxcdn.bootstrapcdn.com/bootstrap/3.3.0/css/bootstrap.min.css" rel="stylesheet" id="bootstrap-css"> <script src="//maxcdn.bootstrapcdn.com/bootstrap/3.3.0/js/bootstrap.min.js"></script> <script src="//code.jquery.com/jquery-1.11.1.min.js"></script> <!------ Include the above in your HEAD tag ----------> <div class="panel-group" id="accordion1"> <div class="panel panel-default"> <div class="panel-heading"> <h4 class="panel-title"><a data-toggle="collapse" data-parent="#accordion1" href="#collapseOne"> Collapsible Group #1 </a></h4> </div> <div id="collapseOne" class="panel-collapse collapse in"> <div class="panel-body"> This is a simple accordion inner content... </div> </div> </div> <div class="panel panel-default"> <div class="panel-heading"> <h4 class="panel-title"><a data-toggle="collapse" data-parent="#accordion1" href="#collapseTwo"> Collapsible Group #2 (With nested accordion inside) </a></h4> </div> <div id="collapseTwo" class="panel-collapse collapse"> <div class="panel-body"> <!-- Here we insert another nested accordion --> <div class="panel-group" id="accordion2"> <div class="panel panel-default"> <div class="panel-heading"> <h4 class="panel-title"><a data-toggle="collapse" data-parent="#accordion2" href="#collapseInnerOne"> Collapsible Inner Group Item #1 </a></h4> </div> <div id="collapseInnerOne" class="panel-collapse collapse in"> <div class="panel-body"> Anim pariatur cliche... </div> </div> </div> <div class="panel panel-default"> <div class="panel-heading"> <h4 class="panel-title"><a data-toggle="collapse" data-parent="#accordion2" href="#collapseInnerTwo"> Collapsible Inner Group Item #2 </a></h4> </div> <div id="collapseInnerTwo" class="panel-collapse collapse"> <div class="panel-body"> Anim pariatur cliche... </div> </div> </div> </div> <!-- Inner accordion ends here --> </div> </div> </div> </div>