The solvent-free catalytic oxidation of toluene using molecular oxygen over metalloporphyrin/N-hydroxyphthalimide (NHPI)/cetyl trimethyl ammonium bromide (CTAB) has been developed. The results showed that the type of metalloporphyrin used, catalyst loading, reaction temperature, and the flow rate of oxygen all influenced the conversion of toluene and the selectivities of the products. Furthermore, a co-catalysis was observed between metalloporphyrin, NHPI, and CTAB. The toluene conversion was significantly improved from 10.74 to 40.95 mol% after adding CTAB to the reaction mixture. Based upon experimental observations, a possible mechanism was also proposed for the present oxidation.