Rates of benzene formation on Mo/HZSM-5, H-ZSM-5 and Mo/SiO2 were measured with different reactants: methane, mixture of C2H4/H-2/N-2 and mixture of C2H2/H-2/N-2. Since the rate of benzene formation starting from C2H4/H-2/N-2 is higher on Mo/H-ZSM-5 compared to H-ZSM-5 it is concluded that the aromatization of methane on Mo/H-ZSM-5 is not going via ethylene which is aromatized over acid sites. Another reaction pathway is proposed.