Electropolymerization of carbazole and its copolymers onto carbon fibers were performed by potentiodynamic and potentiostatic methods. Electrocoated polymer thin films on carbon fiber microelectrodes (CFME) were characterized by combination of a variety of techniques, i.e., cyclo-voltammetry, electrochemical impedance spectroscopy, X-ray photoelectron spectroscopy (XPS), reflectance FTIR spectroscopy (FTIR-ATR). From XPS results the peak at 285.7 eV is assigned to C-S bonding, for the poly[methylthiopheneco-carbazole]. Two distinct S2p peaks in a ratio of 3/2 was observed, which can be assigned to S in polaronic (binding energy: similar to 164.7 eV) and S in bipolaronic forms. Broad band in FTIR-ATR centred in similar to 3100 cm(-1) supports these findings. S and N contents of copolymeric films (XPS) formed (at different initial feed ratio of monomers [Cz](0)/[MeTh](0) = 0.35-1.85) on the CFME surface copolymeric composition was found to be ranging from 1 to 16 carbazole unit against I MeTh unit in the resulting chain. (c) 2006 Elsevier B.V. All rights reserved.