Flow fields in bipolar plates of Proton Exchange Membrane fuel cells distribute fuel and oxidant over the reactive sites of the membrane electrode assembly. Bipolar plates are typically graphite with parallel or serpentine channels as flow fields. Drawbacks of graphite include weight, fabrication inaccuracy, cost, porosity, and brittleness. In this paper, open-cell metal foam is experimentally investigated as a flow field for a new bipolar plate design. Using experiments, the performance of the conventional bipolar plate/flow field was directly compared to that of the metal-foam designs at the same operational conditions. Results show that the cell current, voltage and power density were improved and temperature and pressure distribution on the membrane were even. As importantly, the conversion efficiency was higher for the metal-foam design, and the weight was reduced significantly.