Composite electrodes for supercapacitors are prepared via chemical polymerization of pyrrole (Py) on the surface of a porous graphite fiber matrix. The capacitance properties are investigated with cyclic voltammetry (CV), ac impedance spectroscopy and charge-discharge tests. These electrodes show a specific capacitance of about 400 F g(-1) and a Coulombic efficiency of 96-99%. This indicates that the dipping method is quite suitable for the modification of carbon-based porous graphite fiber to improve the performance of electrodes which can be used in supercapacitors. (C) 2002 Elsevier Science B.V. All rights reserved.