The Al-Si-Cu-Mg cast alloy was modified with additions of Ti-V-Zr to improve the thermal stability of intermetallics at increased temperatures. A combination of electron microscopy, electron backscatter diffraction, and high temperature X-ray diffraction was explored to identify phases and temperatures of their thermal stability. The micro-additions of transition metals led to formation of several (AlSi)(x)(TiVZr) phases with D0(22)/D0(23) tetragonal crystal structure and different lattice parameters. While Cu and Mg rich phases along with the eutectic Si dissolved at temperatures from 300 to 500 degrees C, the (AlSi)(x)(TiVZr) phases were stable up to 696-705 degrees C which is the beneficial to enhance the high temperature properties. Findings of this study are useful for selecting temperatures during melting and heat treatment of Al-Si alloys with additions of transition metals. (C) 2014 Crown copyright and Elsevier B.V. All rights reserved.