Titanium dioxide thin films were deposited on glass substrates and on fluorine doped tin oxides at room temperature by DC magnetron sputtering at different working gas pressures and were evaluated using photocatalytic degradation of an organic compound. The structural properties of the films were studied by electron microscopy techniques and Atomic Force Microscopy. Numerous structural defects were detected for samples deposited at 16 mTorr and it was associated with the highest photo-degradation rate. Also small band gap shift in titanium dioxide films was detected for different gas pressures. These behaviors are related with structural details derived from the synthesis conditions and the influence of structural defects on the photocatalytic activity is discussed. (c) 2005 Elsevier B.V. All rights reserved.