Bilayers formed by combinations of conducting polymers, polypyrrole (PPy) or poly(N-methylpyrrole) (PMPy), as anion exchangers, and the above materials with immobilized poly(4-styrenesulphonate) anions as cation-exchanging matrices, PPy(PSS) or PMPy(PSS), were studied on glassy carbon electrodes using cyclic voltammetry. The electrochemical response is dependent on the formal potentials of the constituent polymers and the permeability of the outer matrix to charge-compensating ions. On the basis of electrochemical measurements and EDAX spectroscopy, for PPy(PSS)(inner)/PMPy(outer) and PMPy(PSS)/PMPy bilayers, the inner film was found to be permanently oxidized, independently of the electrode potential. This was caused by impermeability of the outer layer to cations accompanying the charge/discharge processes of the inner polymer. Charge-transfer reactions of redox electrolytes were studied on rotating disk electrodes covered with polymer bilayers. It was demonstrated that the reaction rate may be controlled by a slow charge transfer between both polymer films (for the Eu3+/Eu2+ couple) and by the Donnan potential prevailing at the outer polymerelectrolyte solution interface (for the Fe(CN63-/4- couple).