A simple method is described for the preparation of activated carbon fibers (ACFs) coated with graphite nanofibers (GNFs). Low-pressure-plasma mixed-gas (Ar/O-2) treatment of the ACFs led to the growth of GNFs on their surface. The growth was greater at higher power inputs, and from TEM observations the GNFs were seen to be of herringbone type. It was found that the N-2 adsorption capacity of the ACFs did not sharply decrease, and that volume resistivity of the ACFs enhanced as a result of this treatment. (C) 2007 Elsevier Inc. All rights reserved.