The photooxidation of acetaldehyde on SrTiO3 has been studied using UV-vis irradiation in the range of 2.1-5.0 eV. It has been found that a large fraction of acetaldehyde undergoes aldol condensation during dark oxidation forming crotonaldehyde. However, in presence of UV light, the formation of CO2 and other partially oxidized species was observed. The infrared assignment of surface species was used to explore the photochemical reaction. (C) 2007 Elsevier B.V. All rights reserved.