The photocatalytic degradation of Ampicillin was investigated under sunlight (coordinates: 13 deg 0 0 40 00 N, 74deg 47 0 44 00 E) for 3 h from 12 to 3 p.m.). An average temperature and an average irradiation intensity of 33 deg C and 84 000 (+/-)6,000 lx were recorded.The experimental runs were performed with 200 mL aqueous solution containing 10 mg L-1 of either antibiotic in a glass beaker of dimensions 100 ,50 mm. Before irradiation under sunlight, the reactor was placed in the dark for 30 min to attain adsorption-desorption equilibrium. Further analysis of the degraded samples was carried out after filtration and centrifugation to remove the suspended catalyst particles. The experiment was carried out in duplicate.