 <p>Try this :</p> <pre><code> &lt;%= f.simple_fields_for :picture do |pic| %&gt; &lt;div class="fileupload fileupload-new" data-provides="fileupload"&gt; &lt;div class="input-append"&gt; &lt;div class="uneditable-input span3"&gt; &lt;i class="icon-file fileupload-exists"&gt;&lt;/i&gt; &lt;span class="fileupload-preview"&gt;&lt;/span&gt;&lt;/div&gt; &lt;span class="btn btn-file"&gt;&lt;span class="fileupload-new"&gt;Select file&lt;/span&gt; &lt;span class="fileupload-exists"&gt;Change&lt;/span&gt; &lt;%= pic.input :image, :as =&gt; :file, :label =&gt; "upload a photo" %&gt; &lt;/span&gt; &lt;a href="#" class="btn fileupload-exists" data-dismiss="fileupload"&gt;Remove&lt;/a&gt; &lt;/div&gt; &lt;/div&gt; &lt;% end %&gt; </code></pre> <p>Just insert <code>erb</code> into bootstrap's html.</p>