Three ternary liquid systems, {dodecane + butylbenzene + [bmim]PF6, [hmim]PF6, or [omim]PF6}, were studied at 313 K and 333 K and atmospheric pressure. Equilibrium tie-line data were measured and plotted for all systems. The effects of the alkyl group in 1-alkyl-3-methylimidazolium hexafluorophosphate, temperature, and solvent-to-feed ratio upon solubility, selectivity (S), and distribution coefficient (K) were investigated. The liquid-liquid equilibrium (LLE) data were correlated sufficiently with both universal quasichemical activity coefficient (UNIQUAC) and nonrandom two-liquid (NRTL) models, and the interaction parameters between each of the three pairs of components for the UNIQUAC and the NRTL models were estimated as a function of temperature. The root-mean-square deviations between the correlated results and experimental data were calculated and found to be satisfactory.