Kinetics of oxidation of 3-Methylindole by KBrO3 in aqueous acetic acid medium has been investigated. The reaction follows a total second order, first order each with respect to [3-Methylindole] and [KBrO3]. The rate of the reaction was not affected by added [H+]. Variation of ionic strength (μ) had no influence on the rate. Increase of percentage of acetic acid decreased the rate. Absence of any polymerization indicated a no radical pathway. Activation and thermodynamic parameters have been computed. A suitable kinetic mechanism based on these observations is proposed. The reactivity of KBrO3 towards 3-Methylindole was found to be higher than that with peroxomonosulphate and peroxodisulphate. The corrosive studies are performed using weight lose method by dipping the mild steel panels in 1M HCl solution.