Acid-catalyzed esterification of benzoic acid with ethanol was investigated in a continuous tubular dow reactor heated by microwaves. The microwave reactor operated at medium pressure and high temperature conditions. Esterification was catalyzed with sulfuric acid and with ion exchange resins. Kinetic parameters of esterification were determined in a stirred glass vessel using conventional heating. A mathematical model was proposed to describe temperature profiles and to predict the conversion of the reaction in the tubular flow microwave reactor. The calculated conversions of benzoic acid based on predicted temperature profiles agree with experimental data. The operating conditions in the microwave reactor allowed us to achieve high conversions at relatively low residence times. (C) 2000 Elsevier Science S.A. All rights reserved.