This paper presents the results of identifying and analyzing the phases present in the microstructure of 4 aluminum piston alloys with different chemical composition. Optical microscopy and scanning electron microscopy were used to study the microstructure of the samples and EDS analysis was used to identify thecomposition of the phases. The phase stoichiometry was identified by comparing the results of EDS analysis with the results reported in the studied literature. The results show that different intermetallic phases can appear depending on the chemical composition of the microstructure of aluminum piston alloys