In the present investigation photocatalytic degradation of an antibiotic rifabutin in aqueous solution with TiO2 as photocatalyst has been investigated under UV irradiation. The efficiency of degradation was quantified by several parameters such as effect of initial concentration, catalyst loading, pH and addition of H2O2 as a co-oxidant. The effect of operational parameters on the decolourisation and degradation under UV irradiation in TiO2 suspension has been investigated to find out the optimum conditions.