The performances of platinum supported on carbon nanofibers (Pt/CNFs) and Pt nanoclusters on carbon Cloth (pt(nano)/CC) as alternative electrodes for PEM fuel cells are compared with those of a commercial Pt-carbon black on carbon Cloth electrode in a I cm(2) fuel cell working at room temperature. Carbon nanofibers were grown by chemical vapour deposition on two different types of microshaped carbon supports (Felt and Cloth) and then Pt was deposited on these nano/micro composite carbon supports. The analysis of the results and in particular of the polarization curves indicate that (i) both Pt-nano/CC and Pt/CNFs materials are better electrocatalysts than commercial one and (ii) Pt-nano/CC gives the lowest ohmic losses while Pt/CNFs materials give the lowest mass transfer losses. Further studies and a better membrane and electrodes assembly (MEA) engineering are necessary to further validate the results, but these preliminary analysis pointed out that new electrode materials based both on Pt nanoclusters and carbon nanostructures (nanofibers/nanotubes) could be very interesting for fuel cells applications. (c) 2005 Elsevier B.V. All rights reserved.