In the present study the influence of the hydrophobic material (Teflon, polytetrafluoroethylene) content in the gas diffusion electrodes (anode and cathode) on the performance of a H(2)/O(2) proton exchange membrane fuel cell is reported. The potential-current (E-I) evaluation of the fuel cell indicated that a combination of 10 and 30 wt% of Teflon, respectively, in the cathode and anode gave the best results. (C) 2002 International Association for Hydrogen Energy. Published by Elsevier Science Ltd. All rights reserved.