By combining non-thermal plasma and photocatalysis a synergy effect has been observed in low concentrated gaseous isovaleraldehyde oxidation in air. The study of the behavior in isovaleraldehyde oxidation by the separate processes has shown that this synergy effect could be due to the activation by UV on TiO2 of the ozone produced by the non-thermal plasma. According to the results, plasma-photocatalysis system significantly increases the efficiency of isovaleraldehyde removal and tends to favor the complete mineralization of isovaleraldehyde. It means that plasma-photocatalysis system could be a relevant method for the removal of low concentrated volatile organic compounds from air. (C)2012 Elsevier B.V. All rights reserved.