The direct methanol fuel cell experiences performance decay at high current densities due to mass transfer limitations. The dominant mass transfer limiting mechanism at high methanol/water feed rates and low methanol feed concentrations has been attributed to the slow diffusion of methanol through the porous diffusion layer of the anode. In this study, fluid oscillations were induced in the feed to the anode of a DMFC and significant performance improvements were observed at high current densities. It was found that the improvement in measured limiting current densities over steady flow operation was as large as twofold and the peak power density increased by as much as 30%. A model is presented which predicts the experimental values of limiting current density as a function of the Peclet number in the porous diffusion layer of the DMFC anode. (C) 2008 American Institute of Chemical Engineers.