<p>Sb-Zn-based alloys are interesting for low-temperature thermoelectric applications. For the enhancement of thermoelectric properties, indium is seen as a promising alloying addition. The knowledge of the ternary In-Sb-Zn alloys solidification path is important for synthesis of materials with required properties. Thirty In-Sb-Zn alloys were prepared, and their as-cast microstructures were analysed. Alloys were produced by melting high-purity components in evacuated quartz ampoules, and their microstructures were characterized by scanning electron microscopy (SEM) with energy-dispersive spectroscopy (EDS) and x-ray diffractometry (XRD). Liquidus projection of the ternary In-Sb-Zn system is determined based on experimental results and phase diagrams of limiting binary systems. There are nine primary solidification phase regions. In addition to terminal solution phases and five binary compounds, one ternary compound exists in the system: Zn₅Sb₄In₂.</p>