Isobaric vapor - liquid equilibria (VLE) for the ethanol + water + [emim][triflate] ternary system have been obtained at 100 kPa using a recirculating still. The ethanol + water binary system was also obtained. Furthermore, claw were simulated with the Mocks electrolyte nonrandom two-liquid (NRTL) model, using the solvent solvent interaction parameters obtained from VLE data of the ethanol + water system and taking the solvent ionic liquid (1L) interaction parameters for the other binary systems from previous works. The agreement between experimental and calculated data is very good, showing the predictive capacity of the model. The addition of [emim][triflate] produces the disappearance of the ethanol + water azeotrope when the mole fraction of ionic liquid in the liquid phase is greater than 0.023 at 100 kPa The effect of [emim][triflate] on the ethanol + water system has been compared with that produced by other tonic liquids reported in the literature