Binary magnesium-silver (Mg-Ag) alloys were designed as antibacterial material to treat infections in an implant site. The mechanical and electrochemical measurements were performed on three casting Mg-Ag alloys under cell culture conditions. The composition and distribution of the corrosion layer was analyzed by microscopy and X-ray photoelectron spectroscopy. In cell culture media, Mg-Ag alloys show higher, but still acceptable general corrosion rates while less susceptibility to pitting corrosion than pure Mg with increasing content of silver. This study indicates that Mg-Ag alloys have satisfactory corrosion properties and much better mechanical properties than pure magnesium as a functional biodegradable material.