The potential of graphite nanofiber (GNF)-Poly(3,4-ethylenedioxythiophene) (PEDOT) composite is explored as a catalyst support for polymer electrolyte fuel cells (PEFCs). Due to electron accepting nature of GNF and electron donating nature of PEDOT, the monomer EDOT adsorbs on the surface of GNF due to strong electrostatic pi-pi interaction. Pt nanoparticles are impregnated on GNF-PEDOT composite by ethylene glycol reduction method and their effects on electro catalytic activity for oxygen reduction reaction (ORR) are systemically studied. Pt particles supported on GNF-PEDOT with catalyst loading of 0.2 mg cm(-2) exhibit a peak power density of 537 mW cm(-2) at a load current density of 1120 mA cm(-2), while it was only 338 mW cm(-2) at a load current density of 720 mA cm(-2) in case of Pt particles supported on pristine GNF. The superior behavior of GNF-PEDOT supported Pt catalyst could be exclusively credited to the high graphitic nature of GNF and their mild functionalization with PEDOT increasing uniform dispersion of Pt. Indeed, the non-destructive functionalization of GNF with conducting polymer, such as PEDOT, makes them promising catalyst-supports for PEFCs. Crown Copyright (C) 2013 Published by Elsevier Ltd. All rights reserved.