Department of Studies in Chemistry, Manasagangotri, University of Mysore, Mysore.570 006 Manuscript received 20 February 1989, revised 6 April 1989, accepted 21 April 1989 The kinetics of oxidation of cycloalkanones, viz. cyclopentanone (Cyp) and cycle­hexanone (Cyp) by sodium N-chlorobenzene sulphonamide or chloramine-B (CAB) in hydrochloric and perchloric acid media have been studied at 30o. The rate shows a first order dependence each on [oxidant), [cycloalkanone] and [H+]. Variation of ionic strength of the medium, addition of the reaction product (benzene sulphonamide) and chloride Ion have no effect on the rate. The effect of varying alcohol composition on the rate has been investigated. Plausible mechanism has been proposed in consistent with the experimental results.