Vapor-liquid equilibria of binary mixtures containing high-boiling solutes methoxy-benzene, (hydroxymethyl)-benzene, 1,2-ethanediol, and 1,4-butanediol and ionic liquid [EMIM] [NTf(2)] were studied by using the transpiration method. VLE measurements were carried out over the whole concentration range at different temperatures between 298 K and 363 K. Activity coefficients y(i) of these solvents in the ionic liquid have been determined from these data and are described formally by using the NRTL equation. In addition, vapor pressures of pure solutes methoxy-benzene, (hydroxymethyl)-benzene, 1,2-ethanediol, and 1,4-butanediol have been measured as a function of temperature, and their enthalpies of vaporization have been obtained.