The corrosion failure analysis of Ni-Cu alloy coatings in Nutrient Broth medium and in the presence of two bacteria: Aeromonas salmonicida and Delftia acidovorans, isolated from water pipe system, has been studied using electrochemical techniques. According to EIS data, the low Rct values of Ni-Cu alloy coatings after bacteria incubation indicated that the metabolic products maybe accelerate corrosion. In addition the pH values of the medium did not change throughout the experiment: however, after immersion the pH value decreased for two bacteria and caused corrosion. These situations were verified with creviced corrosion with SEM analysis. (C) 2012 Elsevier Ltd. All rights reserved.