The microstructures and mechanical properties of as cast Mg‐Zr‐Ca alloys were investigated for potential use in biomedical applications. The Mg‐Zr& 8208;Ca alloys were fabricated by commercial pure Mg (99·9 mass-%), Ca (99·9 mass-%) and master Mg‐33 mass-%Zr alloy. The microstructures of the alloys were examined by X-ray diffraction analysis and optical microscopy, and the mechanical properties were determined from tensile tests. The experimental results indicate that the Mg‐Zr‐Ca alloys with 1 mass-%Ca are composed of one single α phase; these alloys with 2 mass-%Ca consist of both Mg2Ca and α phase, and all the alloys exhibit typical coarse microstructures. An increase in Zr increases the strength of Mg‐Zr‐Ca alloys with 1 mass-%Ca, and the formation of Mg2Ca decreases the strength of the alloys. Mg‐1Zr‐1Ca alloy (mass-%) has the highest strength and best ductility among all the studied alloys.