The work described here involved the study of a novel membrane, Sterion (R), as a polymer electrolyte for direct methanol fuel cells (DMFCs). The influence of the methanol concentration and the temperature on the methanol permeability of Sterion (R) L-180 membrane was studied and the results compared with the those obtained with Nafion (R) 117. Both membranes showed similar values of methanol permeability. The performance of a DMFC using the Sterion (R) membrane was investigated with the aid of anode polarization curves and impedance spectra obtained under different operating conditions. A comparison between the performances of Sterion (R) L-180 and Nafion (R) 117 was performed. The Sterion (R) membrane showed better performance in DMFC than the Nafion (R) membrane despite the slightly higher methanol permeability. This finding can be explained in terms of the different internal structures of these membranes, which result from the different methods used in the casting process. The good performance in a DMFC compared to Nations combined with the low cost of Sterion (R) membranes make them interesting candidates for DMFCs. (c) 2006 Elsevier Ltd. All rights reserved.