Poly-3-methylthiophene (P3MT) films were electropolymerised on graphite and indium tin oxide electrodes and characterised by cyclic voltammetry and scanning electron microscopy. The polymerisation was carried out by two different techniques, pulse potential program and constant current density, yielding conducting coated polymeric electrodes. The polymeric films display structural differences depending on the polymerisation method. The conducting properties of the polymers also depend on the electropolymerisation method. Polymeric resistance and stability were studied. P3MT was used as a support for the anchoring of Pt and Ph metal particles. The catalytic oxidation of formic acid was studied with these electrodes and compared with that obtained with graphite/Pt massive electrodes. (C) 2000 Elsevier Science Ltd. All rights reserved.