A study on the isobaric vapor liquid equilibria of the ternary system containing the ionic liquid 1-ethyl-3-methylpyridinium ethylsulfate (EMpyESO(4)) and the azeotropic mixture ethanol + water is presented in this work. Experimental isobaric vapor liquid equilibrium of the ternary system ethanol + water + EMpyESO(4) was determined at 101.3 kPa, together with the vapor liquid equilibria of the binary systems ethanol EMpyESO(4) and water + EMpyESO(4). The experimental data obtained from the binary vapor liquid equilibria were correlated using the NRTL and e-NRTL equations. The NRTL equation was also used to correlate the experimental vapor-liquid equilibrium of the ternary system. With the parameters obtained from these correlations, the evolution of the azeotrope ethanol + water with different amounts of ionic liquid can be studied. The results obtained were compared with the isobaric vapor liquid equilibria data of the system containing this azeotropic mixture with the ionic liquid 1-ethyl-3-methylimidazolium ethylsulfate.