Purpose: AM50 magnesium alloy allows high-energy absorption and elongation at high strength and has good castability. It contains aluminum and manganese. Typically, it is used in automotive industry for steering wheels, dashboards and seat frames. The aim of this paper is to present the results of investigations on the microstructure of the AM50 magnesium alloy in an ingot condition and after hot chamber die casting. Design/methodology/approach: Die casting was carried out on 280 tone locking force hot-chamber die casting machine. For the microstructure observation, a Olympus GX+70 metallographic microscope and a HITACHI S-3400N scanning electron microscope with a Thermo Noran EDS spectrometer equipped with SYSTEM SIX were used. Findings: Based on the investigation carried out it was found that the AM50 magnesium alloy in as ingot condition is characterized by a solid solution structure a with partially divorced eutectic (a + Mg17Al12) and precipitates of Mn5Al8 phase. After hot chamber die casting is characterized by a solid solution structure a with fully divorced eutectic a + Mg17Al12. Moreover, the occurrence of Mn5Al8 phase and some shrinkage porosity has been proved. Research limitations/implications: Future researches should contain investigations of the influence of the die casting process parameters on the microstructure and mechanical properties of AM50 magnesium. Practical implications: AM50 magnesium alloy can be cast with cold- and hot-chamber die casting machine. Results of investigation may be useful for preparing die casting technology of this alloy. Originality/value: The results of the researches make up a basis for the investigations of new magnesium alloys for hot chamber die casting with addition of RE elements designed to exploitation in temperature to 175°C.