The synthesis, layer-by-layer deposition, and electro-copolymerization of precursor polyelectrolyte multilayer ultrathin films with thiophene and carbazole electroactive groups are described. The interest is in observing an electrochemical cross-linking approach towards a highly ordered ultrathin film that contains two types of monomers result in possible layer-limited homo-and copolymerization. A uniform linear growth with alternate deposition of the polyelectrolytes is observed. The multilayer films were then electrochemically polymerized anodically by cyclic voltammetry (CV), which results in copolymerization between two different electroactive groups. Cross-linking of the layers was verified by CV and spectroelectrochernistry data with very good linear electro-copolymerizability.