The kinetics of the transesterification of isopropyl acetate with methanol to methyl acetate and isopropyl alcohol catalyzed by Lewatit MonoPlus S100 H+ was studied in a pressurized batch reactor. In the temperature range 323-338 K, the temperature dependency of the equilibrium constant was found to be K-a = exp[(702/T) - 1.81]. The kinetics was expressed in terms of activities because of the nonideality of the reaction medium. The experimental data were tested with " a pseudohomogeneous model and adsorption based models. The transesterification reaction was found to follow the Langmuir-Hinshelwood-Hougen-Watson mechanism and the surface reaction to be a rate-limiting step.