This paper presents vapor-liquid equilibrium (VLE) data at 101.3kPa for the ternary systems 1-propanol+water+1-ethyl-3-methylimidazolium thiocyanate [emim][SCN] and 1-propanol+water+1-butyl-3-methylimidazolium thiocyanate [bmim][SCN] and their constituents binary systems. The experimental data obtained were correlated using the NRTL, eNRTL and UNIQUAC models. It was found that the addition of these ionic liquids enhance the relative volatility of 1-propanol to water, and the separation ability follows the order of [emim][SCN]>[bmim][SCN]. The results obtained were compared with the VLE data of the system containing this azeotropic mixtures with different imidazolium-based ionic liquids reported in the literature.