In this paper, we have determined densities, rho, refractive indices, n(D), and dynamic viscosities, eta, of two ternary mixtures, 1-propanol + water + 1-ethyl-3-methylimidazolium ethylsufate (EMISE) and 2-propanol + water + EMISE, at 298.15 K over the whole composition range and at atmospheric pressure. Excess molar volumes, V-E, refractive index deviations, Delta n(D), viscosity deviations, Delta eta, and excess free energies of activation of viscous flow, Delta G*(E), have been calculated from experimental data and fitted to Cibulka and Singh et al. equations. The excess properties have been used to test several prediction models.