An energy-saving process, the so-called reactive distillation process, is attracting more and more attention in the chemical industry. This process is based on the simultaneous implementation of chemical reaction and phase equilibria in a process unit. The esterification of acetic acid and isopropyl alcohol is one of the processes that use this technology. In order to understand the thermodynamic behavior of this mixture and its reaction products, isopropyl acetate and water, the vapor-liquid equilibrium (VLE) was measured directly with the chemical reaction considered. The esterification reaction rate of acetic acid and isopropanol mixture is very slow, In this study, para-toluenesulfonic acid was selected as the catalyst to accelerate the chemical reaction. This results in the reaction reaching equilibrium before phase equilibrium so that this complicated problem can be simplified and readily solved. The equilibrium compositions of this mixture at different temperatures were measured. The reaction equilibrium constants were calculated with the collected experimental data and the equations of reaction and phase equilibria. It was found that the reaction equilibrium constant was slightly dependent on temperature. The measured VLE data were correlated by the activity coefficient models of UNIQUAC and Wilson with consideration of the association of acetic acid in the vapor phase. The calculated results show that the correlation was successful as compared with experimental data.