A study of the influence of microwave radiation, at a frequency of 2.45 GHz on the evolution rate of the hydrolytic decomposition of phenyl acetate evolving in a radiated environment, is presented. The experimental data refer to temperatures of 25, 30, 35, 40, and 45degreesC at radiating powers of 500 and 1000 mW and to 35degreesC at the radiating powers of 50, 190, 200, 300, and 400 mW. Experimental data were obtained using the initial rate method and are correlated with a differential procedure. A comparison with the previously obtained results in a nonradiated environment is presented. From this comparison, the catalytic effect of microwave radiation with the reaction evolving in a nonradiated environment is proposed, replacing that running in a solution with catalytic acetate ions. (C) 2004 American Institute of Chemical Engineers.