Liquid–liquid equilibrium data for the ternary systems nonane+benzene+[bmim][PF 6 ], nonane+toluene+[bmim][PF 6 ], nonane+m-xylene+[bmim][PF 6 ], undecane+benzene+[bmim][PF 6 ], undecane+toluene+[bmim][PF 6 ], undecane+m-xylene+[bmim][PF 6 ]) were determined at 298.15K. Binodal curves were obtained by the cloud point method, while tie-line compositions were obtained by density and UV spectrophotometry measurements. In all cases the two-phase region is large and wide. The values of distribution coefficients and selectivities indicate that the ionic liquid [bmim][PF 6 ] is a good solvent for the extraction of aromatic from aliphatic compounds. The consistency of the tie-line data was ascertained by applying the Othmer–Tobias correlation. The experimental LLE data were correlated through the well-known NRTL model for the activity coefficient, with estimation of new interaction energy parameters, using the Simplex minimization method and a composition-based objective function. The results, analyzed in terms of root mean square deviations between experimental and calculated compositions, were considered satisfactory.