This work concentrates on the improvement in the performance of the polymer electrolyte membrane fuel cell (PEMFC) through optimization of the channel dimensions and shape in the flow-field of bipolar/ nd plates. Single-path serpentine flow-field design was used for studying the effect of channel dimensions on the hydrogen consumption at the anode. Simulations were done ranging from 0.5 to 4 mm for different channel width, land width and channel depth. Optimum values for each of the dimensions (channel width, land width and channel depth) were obtained. For high hydrogen consumptions (similar to80%), the optimum dimension value for channel width, land width and channel depth was close to 1.5, 0.5 and 1.5 mm, respectively. Studies on the effect of channel shapes showed that triangular and hemispherical shaped cross-section resulted in increase in hydrogen consumption by around 9% at the anode. Consequently, their use would lead to improved fuel cell efficiency.