In this work, a two-dimensional, two-phase non-isothermal model is developed for DMFC. The natural convection heat transfer at the out surface of the current collector is considered as the thermal boundary conditions to obtain a more realistic simulation of the DMFC working conditions. The heat and mass transfer, along with the electrochemical reactions occurring in the DMFC are modeled and numerically solved by a self-developed simulation code. The numerical results show that cell performance is enhanced with the increase in the inlet temperature. The distribution of temperature in the DMFC mainly depends on the inlet temperature of the dilute methanol aqueous in the anode side. The mean temperature of MEA and temperature difference in MEA increase with the increase in current density and the profiles show the same trend. With the decrease in MEA thermal conductivity and the increase in the inlet temperature the temperature difference in MEA becomes larger. (C) 2010 Professor T. Nejat Veziroglu. Published by Elsevier Ltd. All rights reserved.