In the frame of the IUPAC Project entitled Thermodynamics of ionic liquids, ionic liquid mixtures, and the deVelopment of standarized systems, 1-hexyl-3-methylimidazolium bis(trifluoromethylsulfonyl) imide, [C 6 mim]-[NTf 2 ], was selected as the "model" ionic liquid to perform round-robin measurements on a series of ionic liquid properties. In this work, the temperature-composition liquid-liquid equilibria of this ionic liquid with linear alkan-1-ols, C n H (2n+1) OH, with n) 4, 5, 6, and 8, were determined at a nominal pressure of 0.1 MPa and up to 50 MPa for n) 4, 5, and 6. Excess molar volumes, V E , of mixtures of this same ionic liquid with linear alkan-1-ols, C n H 2n+1 OH, with n ranging from 2 to 5, were measured at a nominal pressure of 0.1 MPa. The consistency between the two sets of experimental data (phase diagrams and V E) was analyzed from a theoretical perspective; we noticed that as the alkyl chain length, n, of the linear alcohol varies both the pressure dependence of the phase diagrams and the critical excess molar volume change sign.