<p>Bi–Sb–Te alloys are known as the current dominant materials for thermoelectric cooling applications used at near room temperatures. In this work, the available literature data on thermodynamic properties and phase equilibria of the Bi–Sb, Bi–Te, Sb–Te, and Bi–Sb–Te systems are critically reviewed and evaluated. Thermodynamic assessments of the Bi–Sb, Bi–Te, Sb–Te, and Bi–Sb–Te systems are then performed based on the reliable experimental thermochemical and phase equilibrium data. The entire liquid solution phase is modeled using the modified quasi-chemical model in pair approximation. The compound energy formalism and the regular solution model are used for the Gibbs energies of the solid phases. The homologous series of Bi–Sb-rich phases, [(Bi, Sb)₂]_n[(Bi, Sb)₂Te₃]_m, are modeled as one single solid solution phase. One set of self-consistent thermodynamic model parameters is optimized for the Bi–Sb–Te ternary system, which can reasonably describe the reliable thermodynamic and phase equilibrium data.</p>