The decomposition of sodium chlorite was studied in a well-stirred reactor in a pH range of 2-3 and a temperature range of 15-35 degreesC varying the chlorite concentration. The reaction rate was evaluated by analyzing the consumption of chlorite iodometrically. The rate law was established. Reaction was found to be of the first order with respect to both chlorite and acid concentration. Temperature dependence of the reaction was also studied and pre-exponential Arrehenius parameter and activation energy were determined. The optimum conditions to generate chlorine dioxide from sodium chlorite are also highlighted.