The kinetics and mechanism of oxidation of vanillin by N-Bromosuccinimide (NBS) was studied in acidic medium. The reaction exhibited a first order dependence with respect to NBS and fractional order with respect to vanillin and negative fractional order with respect to [H +]. Varying ionic strength has no significant effect on the oxidation rate. The final product of the oxidation was identified as vanillic acid by both spectral and chemical analysis. The rate law explaining all the kinetic results has been evaluated. The activation parameters of the reaction have been evaluated.