A two-dimensional, steady state model for proton exchange membrane fuel cell (PEMFC) is presented. The model is used to describe the effect operation conditions (current density, pressure and water content) on the water transport, ohmic resistance and water distribution in the membrane and performance of PEMFC. This model considers the transport of species and water along the porous media: gas diffusion layers (GDL) anode and cathode, and the membrane of PEMFC fuel cell. The numerical tool chosen for solving these equations is the finite volume method. This allowed us to know better the phenomena taking place inside the porous media. Solving equations of mass transfer as well as transport of species (Darcy equation) allowed us to obtain profiles of concentration of water and reagents within the different layers, for specific operating conditions. Copyright (C) 2011, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.