Tie-line data of the ternary system water + acetic acid + cyclopentyl methyl ether (CPME) at (293.15, 298.15, 303.15, 308.15, 313.15, and 318.15) K are reported. The reliability of the tie-line data was confirmed by using Othmer-Tobias and Hard equations. Distribution coefficients and separation factors were evaluated from the liquid-liquid equilibria (LLE) data. Moreover, the solvent capability of CPME and methyl tert-butyl ether was compared.