Increased concern over the environment degradation due to the emission of green house gases and interest in co-generating electricity and heat have stimulated intensive development of the fuel cell technology. In order to reduce the fuel cell manufacturing costs and to improve its performance, a better understanding of the fuel and oxidant species transport processes within fuel cells is critical. Fuel and oxidant flow distributions through fuel cell channels, usually through distribution manifold, have significant impact on fuel cell performance and efficiency. To this end, this paper presents the effects of the fuel and oxidant flow distributions on multi-channel fuel cell performance using a model of gas flow, heat and mass transfer with the electrochemical reactions for molten carbonate fuel cells. (C) 2002 International Association for Hydrogen Energy. Published by Elsevier Science Ltd. All rights reserved.