Isothermal vapor-liquid equilibrium data for the system methanol + toluene + triphenylbenzylphosphoniurn chloride at five salt molalities {(0.100, 0.500, 1.000, 1.500, and 2.000) mol center dot kg(-1)} have been measured with the help of headspace gas chromatography at (313.15 and 318.15) K. The experimental data were correlated using the electrolyte nonrandom two-liquid model. Several new interaction parameters for this model were obtained and are presented in this work.