Development of nanostructured photocatalysts for harnessing solar energy in energy-efficient and environmentally benign way remains an important area of research. Pure and WO 3 -surface modified thin films of TiO 2 were prepared by magnetron sputtering on indium tin oxide glass, and photoelectrochemical and photocatalytic activities of these films were studied. TiO 2 particles were <50 nm, while deposited WO 3 particles were <20 nm in size. An enhancement in the photocurrent was observed when the TiO 2 surface was modified WO 3 nanoparticles. Effect of potential, WO 3 amount, and radiations of different wavelengths on the photoelectrochemical activity of TiO 2 electrodes was investigated. Photocatalytic activity of TiO 2 and WO 3 -modified TiO 2 for the decolorization of methyl orange was tested.