The results of thermodynamic study of Pb-BiIn section of Pb-Bi-In system done experimentally by Oelsen calorimetry and calculated by general solution model, as well as measurements performed by DTA and optic microscopy in order to investigate phase diagram of the given section, are presented in this paper. Thermodynamic properties, such as integral molar enthalpies of mixing, activities, activity coefficients, partial and integral excess Gibbs energies at 600 and 650 K were determined and comparison between obtained experimental and calculated values were done. Also. based on cooling curves, DTA recordings and optic microscopy results phase diagram was constructed and compared with literature data. (C) 2004 Elsevier B.V. All rights reserved.