The thermodynamics of methane dehydroaromatization in the absence and presence of coke-removing agents was studied using the Gibbs free energy minimization approach. Numerical results indicated that higher temperatures and lower pressures increase methane conversion as well as formation of olefins and aromatics but suppress that of paraffins. Higher H2/CH4 ratios enhance the selectivity of light hydrocarbons but reduce that of naphthalene. Benzene selectivity has a maximum at an H2/CH4 molar ratio of 0.26. Methane conversion exhibits a minimum at an H2O/CH4 molar ratio of 0.07. As the H2O/CH4 ratio increases, formations of heavier hydrocarbons decrease at the expense of CO, CO2, and hydrogen. These results may provide guidelines to improve the process performance.