Liquid-liquid equilibria for the ternary systems water + benzonitrile + propanone and water + benzonitrile + dimethyl sulfoxide were studied in the temperature range (25 to 45) degreesC. Composition analyses of each phase were carried out by gas chromatography. Phase diagrams, including tie lines and plait points, are reported. Distribution curves are shown, and enthalpies of transfer of acetonitrile and propionitrile from water to benzonitrile were calculated.