Vapor-liquid equilibria for the binary system ethyl acetate + acetonitrile and for the ternary system ethyl acetate + acetonitrile + 1-butyl-3-methylimidazolium hexafluorophosphate ([BMIM](+)[PF6](-)) at 101.3 kPa have been obtained with a modified Othmer still. The experimental vapor-liquid equilibrium data were correlated using the NRTL model proposed by Renon and Prausnitz, and the parameters were obtained. The results showed that [BMIM](+)[PF6](-) produced a consistent salting-out effect of ethyl acetate over the whole range of the liquid concentrations, which increased the relative volatility of ethyl acetate to acetonitrile and even eliminated the azeotropic phenomenon when the mole fraction of [BMIM](+)[PF6](-) was up to 0.05.