A two-dimensional steady state model for a PEM fuel cell cathode is described in this work. All the components in the cathode such as the gas manifold, diffusion layer, microporous layer and the catalyst layer are modeled. The effect of the liquid water is taken into account in every layer of the cathode. The model was developed and simulated using a combination of Maple and MATLAB. The combination provides a flexible framework for quickly developing models with various assumptions and different complexities. The cathode catalyst layer was modeled using both macrohomogeneous and spherical agglomerate characterizations. The model is validated using experimental data. During model validation, various assumptions are considered for transport within the porous layers of the cathode. Subsequently, the assumptions and characteristics that best predicts the experimental data are highlighted. The major conclusion of this work is that a model that includes liquid water in all the layers with a flooded spherical agglomerate characterization for the reaction layer best predicts the PEM fuel cell behavior in terms of an i-v characterization for a wide range of reactant flow rates. The utility of the steady state model for the optimization of the cathode catalyst layer design parameters is also described. (C) 2007 Published by Elsevier B.V.