Liquid + liquid) equilibrium (LLE) data were measured experimentally at T = (298.15 or 303.15) K and atmospheric pressure for the (benzene + cyclohexane + dimethyl sulfone (DMSO)) system. The Othmer- Tobias equation was applied to verify the reliability of the data. Based on the data, the selectivity of DMSO was estimated and compared with that of ionic liquids. The highest selectivity coefficient of DMSO can reach beyond 14, which means it is able to compete with some ionic liquids and it would be a good extractant to separate benzene from cyclohexane. At the same time, the NRTL model was used to correlate the data and the results show that the model agrees on the experimental data very well. (C) 2015 Elsevier Ltd. All rights reserved.