The performance of formic acid fuel oxidation on a solid PEM fuel cell at 60 degreesC is reported. We find that formic acid is an excellent fuel for a fuel cell. A model cell, using a proprietary anode catalyst produced currents up to 134 mA/cm(2) and power outputs up to 48.8 mW/cm(2). Open circuit potentials (OCPs) are about 0.72 V. The fuel cell runs successfully over formic acid concentrations between 5 and 20 M with little crossover or degradation in performance. The anodic polarization potential of formic acid is approximately 0.1 V lower than that for methanol on a standard Pt/Ru catalyst. These results show that formic acid fuel cells are attractive alternatives for small portable fuel cell applications.