This work deals with the use of WO3 materials for the removal of DEET, an emerging contaminant, through photocatalytic ozonation using visible light as radiation source. A commercial WO3 and own-made WO3 catalysts with different forms and crystalline structure were synthetized by sol-gel and hydrothermal methods. After catalyst characterization with different techniques, photocatalytic ozonation under visible light radiation was found an efficient process to remove DEET. Monoclinic and/or orthorhombic structure of WO3 seems to favor the catalytic activity more than a developed surface area together with the presence of W reduced states in the presence of ozone. The best catalysts lead to a complete removal of DEET in less than 20 min with mineralization up to 70% in 2 h. (C) 2014 Elsevier B.V. All rights reserved.