Complete catalytic oxidation of toluene was investigated on Cu−Mn doped mesoporous and microporous catalysts, i.e., Cu−Mn/MCM-41, Cu−Mn/β-zeolite, Cu−Mn/ZSM-5 (where SiO2/Al2O3 is either 25 or 38), and Cu−Mn/porous silica, in the presence of excess oxygen. The result shows that mesoporous catalysts have exhibited the highest catalytic activity among these catalysts above. The less amount of coke formation due to the unique mesoporous structures could play a key role in the high activity on the mesoporous catalyst. In addition, the bimetallic Cu−Mn−MCM-41 supported catalyst shows higher oxidation activity than either single metal catalyst, i.e., Cu−MCM-41 and Mn−MCM-41. The highly dispersed Cu−Mn mixed oxides on mesoporous structures probably provide active sites for the complete oxidation of toluene on these mesoporous catalysts.