The phase equilibria for the extraction of aromatics from petroleum naphtha reformate (with a boiling range of 338-403 K) using a mixed solvent of 1-cyclohexyl-2-pyrrolidone (CHP) and ethylene carbonate (EC) have been correlated using the universal function-group activity coefficients model (UNIFAC). The interaction parameters of CHP and EC with different hydrocarbon groups present in the reformate such as CH2 (paraffinic CH2), ACH (aromatic CH), ACCH(2) (aromatic CCH2), and each of the two solvents have been fitted to experimental concentrations of three ternary systems that contain these groups. The extraction runs have been carried out at different temperatures, solvent compositions, and solvent-to-feed ratios. Experimental results compared favorably with those predicted from the UNIFAC method. The optimum extraction conditions were determined by calculation of the minimum energy of separation. In this study these conditions were found to be at a mixed solvent composition of 65% EC (by weight) and 35% CHP. The solvent-to-feed ratio was 1.8 on a volume basis, and the extraction temperature was 329 K.