The high cost of proton exchange membrane (PEM) fuel cells is a major roadblock in bringing fuel cell technology to the general public. This paper presents a simple mathematical model that can be used for fuel cell optimization. The fuel cell's design parameters are chosen so as to globally minimize its total annualized cost for a given power production level. In the process, the fuel cell's feasible operating range is identified and the uniqueness of the global optimum is ascertained. Sensitivity analysis is carried out to identify qualitative trends of the optimal fuel cell design. (c) 2006 Elsevier Ltd. All rights reserved.