Abstract In this study, the effect of zinc addition on the microstructure and mechanical properties of magnesium five-tin (Mg5Sn) alloys was investigated. The powder metallurgy (P/M) method was used for the production of Mg5Sn-xZn (x = 0, 1, 2, 3, 4, and 5 weight percent) alloy after magnesium powders were coated with paraffin. The paraffin coating method was used for the first time in this study in order to prevent the contact of magnesium with oxygen. The experimental results showed that coating magnesium powders with paraffin prevents contact with oxygen. Therefore, Mg5Sn-xZn alloys were produced by P/M technique successfully. The intermetallic phases in the hot-pressed Mg5Sn-xZn alloys were magnesium-two-tin (Mg2Sn) and magnesium-zinc (MgZn) phases. These phases were uniformly distributed at the grain boundaries. Mechanical properties increased with increasing zinc ratios because of the grain refiner effect of zinc. It is concluded that the MgZn phase was obtained only from the Mg5Sn5Zn alloy, which has the highest mechanical properties.