The kinetics of the oxidation of norfloxacin by alkaline permanganate has been studied spectrophotometrically at 25.0 degrees C and at constant ionic strength of 0. 10 mol dm(-3). The oxidation products were identified by LC-ESI-MS technique and other spectral studies. The stoichiometry was found to be 1:2, that is, I mol of norfloxacin reacted with 2 mol manganese(VII). The reaction was first order with respect to manganese(VU) concentration. The order with respect to norfloxacin was found to be less than unity (0.75). Increase in alkali concentration increased the rate. The order with respect to alkali concentration was also less than unity. The effect of added products, ionic strength, and dielectric constant of the medium was studied on the rate of reaction. A suitable mechanism was proposed on the basis of experimental results. The reaction constants involved in the different steps of the reaction mechanism were calculated. The activation parameters with respect to the slow step of the mechanism was determined and discussed.