Liquid-liquid equilibria have been measured for the systems acetone + methanol + n-alkane (C-6-C-8) at 278.15, 288.15, and 298.15 K. Phase compositions were measured by gas chromatography from samples splitted isothermally in a glass stirred device. The tie line data were correlated with the UNIQUAC model and the corresponding fitting parameters being gathered. The UNIFAC group contribution method and its modifications were applied to test their capability to predict liquid-liquid equilibrium, only poor accuracy being obtained for these ternary systems.