The phase diagrams of the CuInS 2 -Sb 2 S 3 and CuInS 2 -Bi 2 S 3 systems were investigated using X-ray powder diffraction and differential thermal analysis. Based on these results, the compositions for the growth of the CuInS 2 single crystals from CuInS 2 -Sb 2 S 3 and CuInS 2 -Bi 2 S 3 melts were selected and Bridgman crystal growth process was performed. The investigation of the obtained single crystals using X-ray powder diffraction and optical absorption spectra indicates that the incorporation of the solvent atoms into the crystal lattice is absent.