Isobaric vapor-liquid equilibrium data for the ternary system ethyl acetate + acetonitrile containing 1-butyl-3-methylimidazolium trifluoromethanesulfonate ([BMIM]OTf) have been measured using a modified Othmer still at 101.3 kPa. With the addition of the ionic liquid [BMIM]OTf, the curve of the ternary system deviates from the line of the ethyl acetate+acetonitrile binary system. When the mole fraction of [BMIM]OTf increased, the deviation was greater. [BMIM]OTf has an obvious salt effect, which caused the elimination of the azeotropic phenomenon observed in the ethyl acetate-acetonitrile system. The experimental values were correlated by the NRTL model with a good consistency. 