Liquid-liquid equilibrium (LLE) data for four ternary systems comprising cyclohexane + (benzene, toluene, ethylbenzene, or cumene) + sulfolane have been measured at 303.15 K and at atmospheric pressure. The LLE data for a six-component system including (cyclohexane + benzene + toluene + ethylbenzene + cumene + sulfolane) has also been measured at the above conditions. The reliability of the experimental data was tested using the Othmer-Tobias correlation. The LLE data were then analyzed using a UNIFAC model with group-interaction parameters extracted from the UNIFAC-LLE data bank and a NRTL version with temperature-dependent binary parameters determined from the experimental LLE data (NRTL/2), both as programmed by the Aspen Plus simulator. Based on the analysis of these data, both models represented the experimental data with sufficient accuracy as revealed from the very small values of the root mean square error and the average absolute deviation in composition.