Using postpolymerization functionalization, we have prepared a new solution-processable electroactive polymer combining electrochemical properties of poly(thiophene)s and oligoanilines. The elaborated procedure consists of three steps. First, 3-octylthiophene and ethyl 3-thiopheneacetate are copolymerized to give poly(3-octyl-2,5-thienylene-co-3-methylene-ethylcarboxylate-2,5-thienylene)-the precursor polymer. The precursor is then hydrolyzed, and in the last step, aniline dimer is attached to it via amidation reaction. UV-vis-NIR and Raman spectroelectrochemical studies combined with cyclic voltammetry show that, as expected, both poly(thienylene) main-chain and dianiline side groups can be oxidatively doped, the latter adopting, upon oxidation, the structure of semiquinone radical cation.