The study of steam reforming of ethanol in micro-channels in a plate-type reformer has been carried out to understand the fluid mechanics, heat transfer and kinetics of ethanol conversion to hydrogen for fuel-cell applications. Heat exchange between alternate channels of combustion flue gas and steam-ethanol mixture has been considered, involving co-flow or counter-flow configurations. Combustion reactions are observed to be completed close to the entry. This results in higher rates of conversion for the co-flow configuration, owing to higher heat transfer rates at the entry. It is shown that end effects are felt only in the outer-most channels and hence a symmetric reformer channel analysis is adequate to predict the performance of a multi-channel reformer system. In the axial direction, the flow, temperature and concentration fields attain fully developed profile form at a short distance from the inlet. At larger axial distances, the velocity profile undergoes mild variations due to changes in the gas density. The temperature and concentration profiles become flat, indicating the weak role played by diffusive transport on the reforming process. In fact, dimensionless temperature and concentration profiles are identical within the reformer channel, leading to the conclusion that the reforming reaction is primarily controlled by conjugate heat transfer between the flue gas and reformer channel systems. The heat transfer area and convective film resistances in the flue gas and reformer channels play a major role in influencing the conversion efficiency. Thus a reformer with relatively shorter length, larger width and larger channel gap gives rise to higher ethanol conversion efficiency, in parallel flow heat exchange configuration.