Composite membranes based on recast Nafion with the inclusion of chabazite and clinoptilolite as fillers were used to increase the operation temperature of direct methanol fuel cells (DMFCs). Membranes containing different amounts (3 and 6 vol%) of these zeolites were prepared. The electrochemical behaviour of the composite membranes was investigated at different temperatures (from 90 up to 140 degrees C). Similar performances (around 350-370 mW cm(-2) under oxygen feed, 200-210 mW cm(-2) under air feed, at 140 degrees) were recorded for the cells based on the composite membranes with 3 and 6 vol% of zeolite filler. Cell resistance measurements showed an improvement of the water retention properties at high temperature for the composite membranes compared to bare Nation. (C) 2005 Elsevier Ltd. All rights reserved.