The kinetics of oxidation of ethylenediaminetetraacetic acid (EDTA) by N-bromosuccinimide (NBS) in aqueous alkaline media was investigated at 25 degreesC. Analysis of the results showed the reaction is first order with respect to [NBS] and apparently less than unit order each with respect to [EDTA] and [alkali]. The influence of the reaction products, ionic strength, temperature effect and dielectric constant of the medium on the rate of reaction was studied. The proposed mechanism is consistent with the observed kinetics. The reaction constants involved in the mechanism were derived. There is a good agreement between the observed and calculated rate constants under different experimental conditions.