The synthesis and characterization of a novel donor acceptor donor type bis(3,4-ethylene-dioxythiophene)-(4,4'-dinonyl-2,2'-bithiazole) comonomer and its electrochemically prepared polymer on carbon fiber, Pt button and ITO plate is reported in this paper. Cyclic voltammetry of the polymer in 0.1 M Et4NBF4/CH2Cl2 exhibits a very well defined and reversible redox processes and this co-monorner can be either p-doped or n-doped. The half-wave oxidation potentials of the polymer (E-1/2) were observed at 0.303 and 0.814 V versus Ag/AgCl. The polymer is electrochromic; the onset for the pi-pi* transition (E-g) of 1.75 eV with lambda(max) at 2.15 eV and the homogeneous and high quality film of the polymer is stable of its optical properties offering fast switching time which is less than 0.25 s. The morphological studies reveal that the polymer was deposited as a continuous and very well adhering film to surface of the carbon fiber microelectrode. All these properties make this polymer favorable for use in electronic devices. (c) 2006 Elsevier Ltd. All rights reserved.