The Bi-Pd system has been critically assessed and optimised using phase diagram information from the literature and new experimental thermodynamic data. High-temperature calorimetry has been used to measure enthalpies of mixing in the liquid phase. The enthalpy of formation of the PdBi compound has been measured by solution calorimetry using a variety of different solvents. Ab initio methods have been used to calculate a value for the enthalpy of formation of PdBi, which has been compared with experiment and a value given by semi-empirical methods.