We develop a pseudo two-dimensional, isothermal transient model for a high temperature proton exchange membrane fuel cell. It takes into account the dynamic change of oxygen concentration in the cathode gas diffusion layer and in the cathode channel. The model can be used to simulate and analyze electrochemical impedance spectra of the cell in both potentiostatic and galvanostatic modes, current interrupt results and step changes in the cell current or potential. The model is validated by fitting experimental data. Copyright (C) 2013, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.