The kinetics of oxidation of inositol (INOS) by permanganate ion in both perchloric and sulfuric acids solutions was studied using a spectrophotometric technique at a constant ionic strength of 1.0 mol dm-3 and at 25°C. In both acids, the reactions showed a first order dependence with respect to [permanganate], whereas the orders with respect to [INOS] were found to be less than unity. The effect of acids concentrations suggests that the reactions were acid-catalyzed with fractionalsecond order kinetics in [H+ ]. Variation of either ionic strength or dielectric constant of the medium had no effect significantly on the oxidation rates. The reactions mechanism adequately describing the kinetic results was proposed. In both acids, the main oxidation products of inositol were identified by spectral and chemical tools as the corresponding monoketone derivative, namely inosose. Under comparable experimental conditions, the oxidation rate in sulfuric acid was approximately three times higher than that in perchloric acid. Regarding to the second order rate constants of these reactions, the activation parameters have been evaluated and discussed.