Ciprofloxacin (CIP) is a famous synthetic chemotherapeutic antibiotic. It is widely found either in water or wastewater. In this study ciprofloxacin was photocatalytically degraded using commercial anatase titanium dioxide (TiO2) under simulated sunlight. The rate of reaction was found to be affected by pH, TiO2 concentration and antibiotic concentration. The best reaction rate was obtained in natural ciprofioxacin pH (5.8) and 1000 mg/L TiO2. More titania concentration was found to reduce the reaction rate because of the limitation in light transmittance. From kinetic studies, the reaction was proved to proceed through adsorption step then photooxidation and obeys pseudo-first order kinetics. (C) 2010 Elsevier B.V. All rights reserved.