The phase relationships of the quasibinary GaSb-Pb section of the ternary Ga-Sb-Pb system were studied by means of the X-ray diffraction (XRD) and optical microscopy. Phase reactions were determined using differential thermal analysis (DTA). Based on this results phase diagram of the GaSb-Pb section was constructed, which was compared with literature data. (C) 2004 Elsevier B.V. All rights reserved.