This paper reports performance data for the direct methanol fuel cell (DMFC) using membrane electrode assemblies using radiation-grafted proton exchange membranes based on polyethylene and ETFE. These membranes exhibited low methanol diffusion coefficients and were thus felt to be potentially useful in reducing possible methanol cross-over from anode to cathode. The membrane electrode assemblies were based on Nafion(R)-bonded carbon-supported catalyst; platinum/ruthenium for the anode and platinum for the cathode. The cell voltage performance of the DMFC, for short duration (<100 h) testing, with these low cost membranes is as good as, or superior to, that of cells based on Nafion(R) under identical operating conditions. However, the stability of contact between the membrane and the catalyst layer re quires improvement before these membranes become real alternatives to materials such as Nafion(R), for the DMFC.