In order to meet the requirements of various applications, considerable efforts have been focused on the new approaches for synthesizing carbon nanotubes. Recently, simple thermal chemical vapor deposition growth technique by pyrolyzing ethyl alcohol has been developed. However, this method needs metallic catalyst. Here, we demonstrate that it is possible to synthesize multi-walled carbon nanotubes without the aid of any catalyst. The as-synthesized products were analyzed by high-resolution transmission electron microscopy (HRTEM). The HRTEM images show that the products are straight multi-walled carbon nanotubes. The synthesis technique of carbon nanotubes is cost-effective because of the catalyst-free process.