The most critical problems to overcome in the PEM (proton exchange membrane) fuel cell technology are the water management. In this work, a seven-layer theoretical model is proposed that includes anode and cathode inlet channels, anode and cathode GDLs (gas diffusion layers), CLs (catalyst layers), and the 117 Nation proton exchange membrane. The mathematical model is a one-dimensional, steady-state, isothermal and isobar to describe the water transport phenomena in PEMFC (proton exchange membrane fuel cell). A rationally chosen set of parameters are considered such as the humidity and the stoichiometry of the inlet gases, the porosity of GDL, and the membrane thickness. The results show that with sufficient levels of humidity, the water management would improve for larger porosities of GDLs or a thinner membrane, and the resistance and over voltage of the membrane can be reduced significantly as well. This model will help to select system parameters so that the fuel cell would not suffer from dehydration and flooding. Also, model predictions were successfully compared to theoretical I-V polarization curves presented by Chen et al. (2007) and Springer et al. (1991). (C) 2012 Elsevier Ltd. All rights reserved.