The corrosion behavior of FeCoNiCrCux high-entropy alloys in 3.5% NaCl solution is reported in this paper. The corrosion resistance has been evaluated using immersion tests and potentiodynamic polarization measurements. Our results show that the increase of copper content in FeCoNiCrCux alloys also increases the tendency to localized corrosion of these alloys. This is due to Cu-rich interdendrite and Cu-depleted (Cr-rich) dendrite in these alloys set up a active/noble cell of appreciable potential difference, and the galvanic action results in preferentially attack along the interdentrites of copper containing high-entropy alloys. (c) 2005 Elsevier B.V. All rights reserved.