A two-dimensional anisotropic model is developed to investigate the impact of local delamination on polymer electrolyte fuel cell (PEFC) performance. Localized interfacial delamination of the membrane parallel to catalyst layer and catalyst layer parallel to diffusion media were found to increase ohmic resistance significantly. As interfacial delamination width and area fraction increases, the ohmic resistance sharply increases in a nonlinear manner. The in-plane resistance and in-plane-to-thru-plane resistance ratio of PEFC components adjacent to the delamination were determined to be the key controlling parameters for increase in ohmic resistance. The membrane is a critical component because of its relatively low conductivity and very thin cross section. Finally, it is shown that under frozen conditions, small interfacial delaminations can result in a greater ohmic loss due to significantly lower membrane conductivity compared to normal operating conditions.