Edit in JSFiddle

<div class="select">
  <select>
    <option value="">Seleccione uno:</option>
    <option value="opcion-1">Opción 1</option>
    <option value="opcion-2">Opción 2</option>
    <option value="opcion-n">Opción N</option>
  </select>
</div>
.select {
  border: 1px solid #ccc;
  width: 140px;
  margin: 50px auto 10px;
  overflow: hidden;
  background: #fff url("http://www.csslab.cl/ejemplos/select/arrowdown.gif") no-repeat 90% center;
}
.select select {
    padding: 5px 8px;
    width: 130%;
    border: none;
    box-shadow: none;
    background-color: transparent;
    background-image: none;
    -webkit-appearance: none;
    -moz-appearance: none;
    appearance: none;
}