The interfacial ohmic losses between the bipolar plate and the MEA can significantly reduce the overall power output from a SPFC. For graphitic bipolar plate materials, these losses are insignificant relative to stainless steel, where the existence of a passive film on the surface greatly reduces electrical conductivity. In this paper we have evaluated different bipolar plate materials, and present long-term fuel cell data for Poco(R) graphite, titanium, 316 and 310 stainless steel. The properties of the passive film on the surface of 316 and 310 stainless steel are markedly different. Although both were adequately corrosion resistant in a fuel cell environment, 310 tended to produce higher fuel cell performance and like 316, no degradation was observed after 1400 h testing. Analysis of the passive film indicated that this increased performance was related to the decreased thickness of the oxide film.