Binary thermodynamic data, successfully used for phase diagram calculations of binary systems In-Sb, In-Zn, and Sb-Zn, were used for prediction of phase equilibria in ternary In-Sb-Zn system. The liquidus projection, invariant equilibria and several vertical sections were calculated using the CALPHAD method. Alloys, situated along three calculated vertical sections, were investigated by differential thermal analysis (DTA). The experimentally determined phase transition temperatures were compared with predicted results. Phase identification of selected samples was done using scanning electron microscopy (SEM) with energy dispersive X-ray micro-analysis (EDS).