Recently manganese substituted I-III-VI2 compounds have been investigated. Their magnetic properties are similar to the paramagnetic transistion metal ion substituted II-VI materials, but their crystal structure is non-cubic resulting in anisotropies in their physico-chemical properties that do not exist in the zincblende structure diluted magnetic semiconductors (DMS) materials. In this paper, we report the phase relations on the pseudobinary cut CuInTe2-MnIn2Te4 based on x-ray diffraction and differential thermal analysis data. The range of chalcopyrite structure alloys of composition Cu1−xMnx□xIn2Te4 is limited to x<0.52 due to an eutectic at x=0.74, T= 734°C. A second eutectic exists at x = 0.97, T = 737.5°C. A heretofore unknown congruently melting compound exists in between the two eutectics at x= 0.85, Tm = 760°C. Also, the thus far unknown melting point of the compound MnIn2Te4 was determined (740°C ). Based on the analyses of the first to freeze parts of directionally solidified melts in this range of liquidus compositions by inductively coupled plasma emission spectroscopy the solidus is constructed.