Experimental data for liquid-liquid equilibria (LLE) of ternary systems of {aromatic (ethyl benzene or p-xylene) + alkane (hexane or heptane or octane) + ionic liquid} at T = 298.15 K and atmospheric pressure were studied. The ionic liquid 1-methyl 3-octylimidazolium thiocyanate [Omim][SCN] was used. The tie lines composition was determined by the gas chromatography and mass balance. The selectivity values were calculated from experimental data. The selectivity values are more than unity which indicate the suitability of IL as a new solvent in extraction of aromatics from alkanes. The reliability of the LLE data was tested by the Othmer-Tobias and Hand equations. The NRTL thermodynamic model was applied for correlating the experimental data. The modelling results show the NRTL model can correlate the experimental data with good accuracy. (C) 2012 Elsevier Ltd. All rights reserved.