The isobaric vapor liquid equilibrium (VLE) data for the cyclohexanone + benzene, cyclohexanone + toluene, and cyclohexanone +p-xylene systems at a pressure of 101.3 kPa were measured with a modified Rose-type recirculating still. The thermodynamic consistency of the experimental data was checked with the Herington, Van Ness, infinite dilution, and pure-component consistency tests. In addition, the VLE data were correlated by the nonrandom two-liquid (NRTL), Universal Quasichemical (UNIQUAC), and Wilson activity coefficient models, and the binary interaction parameters for the three thermodynamic models were regressed. The calculated results for the three models show good agreement with the experimental data. The UNIFAC model was also used to predict the VLE data and presented good results for the three systems.