Nickel-coated carbon fiber (NiCCF) material is of interest to a number of important industry sectors. The present paper reports a complex study of the corrosion performance of 12K (12,000 single filaments) NiCCF composite tows. The corrosion behavior of this material was examined in dilute H2SO4, Cl--based neutral and NaOH solutions, with respect to its potential application in electrochemical cathodic protection and bipolar plate (fuel cell) technologies. The composites were produced by electro- (or electroless NiP) deposition of an ultrathin (ca. 0.3-0.5 mu m) Ni coating onto Hexcel 12K carbon fiber tow. A commercially available, electrodeposited 12K NiCCF product (Toho-Tenax fiber) was used as a reference material. (C) 2008 The Electrochemical Society.