NiO-Bi2O3 nanocomposite was synthesized and characterized. XRD analysis and UV-vis spectroscopy revealed that the two components of the composite retain their independent identity. Nevertheless, the smaller mean crystallite sizes of the NiO and Bi2O3 in the nanocomposite, compared to pure components, suggests the presence of an interaction between the two phases. Consistently the surface area of the nanocomposite is significantly higher with respect to that of the pure components. Photocatalytic activity was estimated for the decolorization of methylene blue and methyl orange. The nanocomposite, NiO-Bi2O3 showed significantly higher activity compared to its components in the pure phase. (C) 2009 Elsevier B. V. All rights reserved.