The catalytic oxidation of isopropanol and o-xylene alone and in mixture was investigated over basic zeolites (CsX and NaX) and an acidic zeolite (HY). For a given temperature, the conversion of VOCs mixture into CO2 increases with the basicity of the zeolite. Results show that VOCs are oxidized through a basic mechanism over NaX, and through an acidic mechanism over HY. Over HY, the presence of isopropanol increases the oxidation of o-xylene, probably because of the formation of isopropyldimethylbenzenes obtained via an acidic mechanism. The addition of platinum over zeolites increases the rate of the VOCs oxidation, this behavior being more pronounced over PtHY maybe because of a higher Pt dispersion. (C) 2007 Elsevier B.V. All rights reserved.