The photocatalytic degradation of Reactive Brilliant Blue KN-R has been investigated under UV irradiation in aqueous suspension of titanium dioxide under a variety of conditions. The degradation was studied by monitoring the change in dye concentration using UV spectroscopic technique. The effects of key operation parameters such as initial dye concentration, catalyst loading, hydrogen peroxide dosage as well as initial pH value on the decolorization extents were studied. The decolorization of the organic molecule followed a pseudo-first-order kinetics according to the Langmuir-Hinshelwood model. Under the optimum operation conditions, approximately 97.7% color removal was achieved with significant reduction in TOC (57.6%) and COD (72.2%) within 3 h. Moreover, the degradation products were analyzed by GC-MS technique and probable pathways for the formation of products were proposed. (C) 2010 Elsevier B.V. All rights reserved.