In the present study, the photocatalytic degradation of 2,4,6-trichlorophenol (2,4,6-TCP) was carried out in a batch reactor under UV light in aqueous solution for 5 h using titania P-25 ( surface area 50 m(2)/g) as a photocatalyst and sodium hypochlorite as an oxidant. Variables studied include catalyst dose (0.25 - 1.25 g/L), pH (2 - 6), and concentration of the oxidant (3.06 x 10(-6) M - 15.3 x 10(-6) M). The rate of degradation was studied in terms of changes in concentration of the pollutant and reduction in chemical oxygen demand. The optimal values of operational parameters leading to 2,4,6-TCP abatement were obtained by using response surface methodology. The percent degradation and COD reduction of 2,4,6-TCP was found to increase with increases in the catalyst dose up to the dose of 1.1 g/L, pH in the range of 4 - 4.5, and oxidant concentration of 9.95 x 10(-6) M.