Department of Chemistry, Khallikote College (Autonomous), Berhampur-760 001, India Manuscript received 1 march 1999, revised 27 December 1999, accepted 3 March 2000 The kinetics of oxidation of anthranilic acid and p-aminobenzoic acid by peroxomonosulfuric acid have been studied in aqueous medium in the pH range 0-6.4 at 308 K. The reactions are second order - first order each in pcroxy acid and in aminobenzoic acid concentration at constant pH. The reactivity of different peroxo species in the oxidation, has been determined. A mechanism consistent with rate-determining nucleophilic attack of the amino nitrogen on the elcctrophilic peroxo oxygen has been propsed.