How to hide exposed sort if view return empty result?
In views-view.tpl.php, just replace this code

&lt;?php if ($exposed): ?&gt;
    &lt;div class="view-filters"&gt;
      &lt;?php print $exposed; ?&gt;
    &lt;/div&gt;
  &lt;?php endif; ?&gt;


with 

&lt;?php if ($exposed &amp;&amp; $rows): ?&gt;
    &lt;div class="view-filters"&gt;
      &lt;?php print $exposed; ?&gt;
    &lt;/div&gt;
  &lt;?php endif; ?&gt;


Cheers