Vapor-liquid equilibria were measured at 101.3 kPa for three binary mixtures and one ternary mixture of 2-propanol, l-chlorobutane, and acetonitrile. Thermodynamic consistency of data for the three binary mixtures was tested using the Herington method. The Soave-Redlich-Kwong equation of state was used to calculate the vapor-phase fugacity coefficients. The experimental vapor-liquid equilibrium data were reduced, and binary parameters for four activity coefficient models, such as van Laar, Wilson, NRTL, and UNIQUAC, were fitted. The four models with their best-fitted parameters were used to predict the ternary vapor-liquid equilibria. A comparison of model performances was made by using the criterion of absolute average deviations in boiling point and in vapor-phase composition.