The present article describes the surface modification of nanostructured titanium dioxide with platinum and silver metals and photocatalytic efficiency of the resulting nanocomposite. Microscopic study revealed that the particle size of homogeneously distributed platinum and silver particles on the surface of TiO2 was in the range of 2-4 nm and 3-20 nm, respectively. The effect of platinum and silver concentrations such as 0.5, 1.0, 1.5, 2.0, and 2.5 wt.% on the photocatalytic activity of TiO2 has been studied. The photocatalytic efficiency of various samples was tested by studying the photo-oxidation of a dye namely acridine orange as probe reaction. The influence of various operational parameters such solution pH, substrate and catalyst concentration, and temperature of the reaction on the photocatalytic degradation of model pollutant has also been investigated. The study showed that the activity of TiO2 was significantly enhanced by depositing an optimum concentration of metals (Pt induced higher degradation as compared to Ag) for the degradation of acridine orange. Alkaline media was found to be favorable for the photodegradation of the model pollutant. (C) 2009 Elsevier B.V. All rights reserved.