This paper presents a numerical modeling, provides an improved understanding of the fundamental transport phenomena inside the PEM fuel cell. The problem is stated in a steady-state, two-dimensional model and Cartesian coordinates system by using a single domain and a control volume method. The model consists of non-linear, coupled partial differential equations representing the conservation of mass, momentum, species, charges and energy with electrochemical reactions that are valid for gas diffusion electrodes, catalyst layers and membrane region. The modeling of bidirectional, non-isothermal and steady problem of PEMFC provides results concerning the species fraction, potential and temperature distribution in different domain. Copyright (C) 2012, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.