A high-temperature mixing calorimetry method has been used for the thermochemical study of the Pd-S system. The standard molar enthalpies of formation of the palladium sulphides were derived by measuring the heat effect associated with the formation of a low-melting (Pd + S) liquid alloy from the elements, and the effects associated with the formation of the same melt from the sulphide investigated and one of the pure constituent elements. The following values are reported for the standard enthalpies of formation for the four sulphides studied : Delta(f)H(m)(o)(PdS, 298.15 K) = -(78.1 +/- 11.0) kJ.mol(-1); Delta(f)H(m)(o)(Pd16S7, 298.15 K) = -(580.1 +/- 36.2) kJ.mol(-1); Delta(f)H(m)(o)(Pd3S, 298.15 K) = -(96.5 +/- 10.5) kJ.mol(-1); Delta(f)H(m)(o)(Pd4S, 298.15 K) = -(99.2 +/- 11.2) kJ.mol(-1).