The effects of Ag-Cu ions on the microbiologically induced corrosion of galvanized steel in the presence of Desulfovibrio sp. and Desulfosporosinus sp. were investigated. The corrosion behavior of galvanized steel was analyzed by potentiodynamic polarization and electrochemical impedance spectroscopy. The biofilm, corrosion products and Ag-Cu ions on the surfaces were investigated by using scanning electron microscopy, energy dispersive X-ray spectrometry and elemental mapping.