The objective of the present paper is to investigate the effect of clamping force on the performance of proton exchange membrane fuel cell (PEMFC) with interdigitated gas distributors considering the interfacial contact resistance, the non-uniform porosity distribution of the gas diffusion layer (GDL) and the GDL deformation. The clamping force between the GDL and the bipolar plate is one of the important factors to affect the performance and efficiency of the fuel cell system. It directly affects the structure deformation of the GDL and the interfacial contact electrical resistance, and in turn influences the reactant transport and Ohmic overpotential in the GDL. Finite element method and finite volume method are used, respectively, to study the elastic deformation of the GDL and the mass transport of the reactants and products. It is found that there exists an optimal clamping force to obtain the highest power density for the PEMFC with the interdigitated gas distributors. (c) 2006 Elsevier B.V. All rights reserved.