The phase equilibria in the Sb–Sb₂S₃–SbI₃ ternary subsystem have been investigated by the differential thermal analysis (DTA) and X-ray diffraction (XRD) analyses. The quasi-binary section SbI₃–Sb₂S₃ restudied and ternary compound SbSI reported earlier was confirmed. Several polythermal sections and the projection of the liquidus surface have been revised. The fields of the primary crystallization, as well as the types and coordinates of non- and monovariant equilibria were determined.