In this paper, the results on the preparation of photocatalytically active thin films will be presented. The films based on TiO2 and were deposited by using sputtering technique as well as by applying combustion CVD methods. For the determination of the photocatalytically properties of the films the decomposition of stearic acid after UV irradiation was investigated by FT-IR measurements. Additionally, measurements of the water contact angles on the surfaces, long-term hydrophilicity measurements and UV-VIS measurements were carried out. It was found for the sputtered films that the photocatalytic properties of the as-deposited films were comparable to commercially available whereas the annealed films showed higher photocatalytic activity. By applying optimal film thicknesses, a strong increase of the transmission value compared to commercially available products could be observed. (c) 2006 Elsevier B.V. All rights reserved.