Surface tensions and liquid densities of ternary mixtures consisting of water + toluene + acetone in the homogeneous region were determined. The pendant drop method combined with axisymmetric drop shape analysis and with an effective temperature control of the measuring cell allowed measurements of surface tension in a temperature range from (288 to 328) K and at pressure of 0.1 MPa. Liquid densities of ternary and binary mixtures of this system at the same temperature range were obtained using a vibration tube densimeter. Binary and ternary surface tensions could be predicted using ideas from the Butler model. This procedure required only surface tension data of the pure components, surface area values (obtained from molar volume), and NRTL parameters taken from the literature. Distribution of substances between bulk and surface could be analyzed using these relationships.