In the present study, vapor liquid equilibrium data (VLE) has been generated for binary system: acetic acid and p-xylene, at atmospheric pressure (96.15 Kpa). The recirculation type of apparatus was used for generating the VLE data for a given temperature and compositions1. The activity coefficients were estimated using Wilson and NRTL models at different composition. It has been seen that experimental data fits well to the predicted data. Further, thermodynamic consistency of experimental data has been confirmed using Redlich- Kister and point to point test methods. It has been found that experimental data is thermodynamically consistent.