Plasma-reforming process has been widely studied for over a decade, with a focus on diverse fuels and plasma parameters for finding the optimum conditions. This study evaluates the effect of thermal activation on the chemistry and energy efficiency of the methane-reforming process. Based on the empirical evaluation, a correlation was found among the methane conversion rate, reaction composition, reactant temperature, and plasma power. Moreover, the plasma chemistry did not change with the reactant temperature within the temperature range evaluated. In addition, it was found that the ratio of the plasma power to the heating input power was an important parameter for enhancing the efficiency of the partial oxidation of methane. Copyright (C) 2013, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.