In this work. an experimental study of the polarisation response of a H-2/O-2 PEFC was carried out at low temperatures as a function of the membrane thickness. Results were analysed using a simplified model describing the transport of water in the membrane. It Is seen that the model equations lead to good fittings of experimental current-potential data for polymer electrolyte fuel cells (PEFC) working with dry hydrogen and with Nafion(R) 115 and 117 membranes. For these membranes, limiting effects due to oxygen diffusion are minimal and the water transport through the membrane is a limiting effect for the cell behaviour at high current densities. With the Nafion(R) 112 membrane, oxygen diffusion effects dominate the characteristics of the current-potential curve.