Nanostructured titania films were implanted with N at energies between 10 and 40 keV and ion dose range 1014 to 5 x 10(16) cm(-2) and the films were characterized using various techniques. The surface morphology of the nanostructured films has been modified with ion implantation as observed using scanning electron microscopy (SEM). From SIMS depth profile analysis the amount of nitrogen was found to increase with increasing ion energy. The profile of N appeared to have a skewed Gaussian curve and the results have been explained using SRIM theoretical simulations. A maximum nitrogen concentration of about 6.08 at% has been quantified by X-ray photoelectron spectrometer (XPS). Transmittance of the films decreases with increasing implantation energy and ion dose due to defects created by the ion implantation. Annealing can remove defects and thereby increase the transmittance of the films. © 2004 Elsevier B.V. All rights reserved.