The photocatalytic activity of TiO2 films deposited on different substrates by the spray-drying method using suspensions of commercially available TiO2 (Degussa P25 or Tronox) as starting material was studied. The influence of the type of the initial TiO2, preparation conditions (temperature of the substrate during the film deposition, temperature of the post-deposition annealing), substrate material (glass, fused silica, stainless steel and graphite), the presence of additives in the spraying suspension (polyethylene glycol, ethylene glycol and acetylacetone) and its sonication before spraying on the morphology, size of crystallites and phase composition (rutile/anatase ratio) was studied. Optimal conditions for spray deposition of the films are suggested. (C) 2009 Elsevier B. V. All rights reserved.