Electropolymerization of polyaniline (Pani) was carried out on different high surface area carbon substrates: carbon fiber and reticulated vitreous carbon (RVC™). Due to the different morphology of the RVC™ substrate, a modification of a well established aniline electrodeposition methodology is proposed. The electrical and morphological characteristics of the resulting Pani films were strongly affected by the chosen substrate and are analyzed, using electrochemical impedance spectroscopy and scanning electron microscopy, in terms of the current penetration profile within the RVC™ electrode. For the films grown on RVC™ the voltammetric waves were wider, the charge-transfer resistance was higher and the morphology more compact.