Sm0.5Sr0.5CoO3-delta (SSC) was evaluated as a bi-functional catalyst for rechargeable metal-air battery cathodes. The catalyst was homogenously dispersed on corrosion-resistant graphitized Vulcan XC-72R carbon powder for the cathode fabrication. For comparison, the air cathode catalyzed with the widely studied perovskite La0.6Ca0.4CoO3 (LCC) was included in the evaluation. Based on the polarization curves, SSC exhibited similar catalytic activities as LCC for both oxygen evolution reaction and oxygen reduction reaction. Furthermore, the air cathode prepared with SSC exhibited an improved cyclic life. These results suggest that SSC is a promising alternative to LCC as a bi-functional catalyst for metal-air battery cathode applications. (C) 2012 Elsevier B.V. All rights reserved.