Nanotechnology is now growing rapidly and meeting various applications in sciences and engineering. Nanotechnology is believed to solve many problems faced by mankind now and in the future. Among the fields in which nanotechnology will play very important role are energy and environment. These applications include the recovery and improvement of environment caused by pollution, efficient use of conventional energies, and development of renewable energies. Today, energy and the environment are among the priority fields that are fully considered by various countries. Therefore, it becomes very strategic to propose a symposium focusing on the applications of nanotechnology in solving the problems of energy and environment worldwide.