The aim of the present investigations was to analyse the phase composition of Ga-Mg-Zn alloys of compositions in the vicinity of the quasicrystalline phase existence. Slow solidification from the melt was performed using home-made apparatus. The sample composition was different for alloys with Ga content varying from 16 at% to 31 at%, Mg from 26 at% to 38 at% and Zn content varying between 40 at% and 52 at%. During the solidification process of the alloys, several types of single crystals were obtained. Polygonal forms of MgZn2 (Laves phase) single crystals crystallised in the shrinkage cavities, single crystals of Ga28Mg42Zn30 and faceted forms of Ga14Mg27Zn59 single crystals were observed in our experiment for the first time. Apart from that relatively large (2 mm x 2 mm) polygonal Mg single crystals crystallised in shrinkage cavities. For some compositions colonies of Zn whiskers were formed throughout the whole volume of sample. The only quasiperiodic phase was found in alloys obtained for composition of Ga24Mg36Zn40, In the case when the original composition differed from that of the icosahedral phase three new phases were found: Ga14Mg19Zn67 and Ga14Mg27Zn59 with symmetry 6/mmm and Ga28Mg42Zn30 with 4/mmm symmetry. All phases coexisted in the whole volume of alloy. (C) 2003 Elsevier B.V. All rights reserved.