We have prepared H+ doped Polyaniline (PANI)/multiwalled carbon nanotubes (MWCNTs), Fe3+ doped PANI/MWCNTs, and H+, Fe3+ codoped PANI/MWCNTs nanocomposites via in situ oxidative polymerization method. The formation of the doped PANI in the composite was confirmed by the FTIR, and Raman spectroscopy. The electrochemical characterizations were carried out in 1 M H2SO4 electrolyte. The H+ and Fe3+ codoped PANI/MWCNTs nanocomposites exhibited specific capacitance of 605 F/g at 2 mV/s scan rate, high enough compared to that of solely H+ doped PANI/MWCNTs and Fe3+ doped PANI/MWCNTs nanocomposites at the same scan rate. Galvanostatic charge discharge test also established the superiority of the H+ and Fe3+ codoped PANI/MWCNTs nanocomposite as a supercapacitor electrode material with maximum specific capacitance of 575 F/g at a constant current density of 1 A/g, and about 93% of initial specific capacitance retention over 500 number of charge discharge cycle. (C) 2013 Elsevier B. V. All rights reserved.