Numerical simulation was carried out to predict the flow, temperature, and current distributions in a polymer electrolyte fuel cell (PEFC). The continuity, momentum, and energy equations with mass and heat source/sink terms produced by chemical reactions are solved using a general computational fluid dynamic codes. A local current density at each point on the electrode surface is calculated as a function of gas pressure, cell temperature, humidity, and partial pressure as well as cell voltage using an empirical electro-chemical equation. The performance was simulated using Nafion 115 membrane with the active area of 100 cm(2) with a serpentine flow channel, which is suited for uniform gas supply. The predictions indicate that flow distribution and current production are affected significantly by each other. This approach can be used to understand and investigate the effects of various parameters, such as the pattern and dimensions of flow channel configurations, operating conditions, such as inlet humidity, reactant utilization ratio, and pressure on the PEFC performance for optimal design. (C) 2003 International Association for Hydrogen Energy. Published by Elsevier Ltd. All rights reserved.