In this study, Delftia acidovorans was isolated from water treatment pipe system and used to demonstrate microbiologically influenced corrosion of NiZn alloy coatings using electrochemical techniques. The surface morphologies and the corrosion products were determined using scanning electron microscopy (SEM) and energy dispersive X-ray spectra (EDS) analysis. Results showed that when the metabolic activity reached maximum level, corrosion activity of NiZn alloy coatings significantly increased in correlation with E-corr, I-corr, QCM and R-ct. Furthermore, crevice corrosion which has been seen due to bacterial adhesion confirms that D. acidovorans plays an important role in corrosion of NiZn alloy coating. Crown Copyright (C) 2012 Published by Elsevier Ltd. All rights reserved.