In this paper, entropy generation in hydrogen enriched ultra-lean counter-flow methane-air premixed combustion confined by planar opposing jets is investigated for the first time. The effects of the effective equivalence ratio and volume percentage of hydrogen in fuel blends on entropy generation are studied by numerical evaluating the entropy generation equation. The lattice Boltzmann model proposed in our previous work, instead of traditional numerical methods, is used to solve the governing equations for combustion process. Through the present study, four interesting features of this kind of combustion, which are quite different from that reported in previous literature on entropy generation analysis for hydrogen enriched methane-air combustion, are revealed. For a given effective equivalence ratio, the total entropy generation number can be approximated as a linear increasing function of the volume percentage of hydrogen in fuel blends for all cases investigated in the present study. (C) 2010 Professor T. Nejat Veziroglu. Published by Elsevier Ltd. All rights reserved.