Specific features of voltammetric studies with modified electrodes are subject of the consideration performed in the review. Basing on the approaches developed in preceding works, three groups of problems are discussed. The first one concerns a regular treatment of quasi-equilibrium cyclic voltammograms of modified electrodes. It is emphasized that singular points of such curves and their form depend on the system parameters (charges of immobile charge carriers, binding of counter-ions with the film fragments). As regards the second group of problems, its existence results from possible effects of the film porosity on the rates of reduction/oxidation processes with participation of particles capable to react on the film/solution interface. The main conclusion followed from the performed discussion is in the possibility of appearing the limiting currents not controlled with tested particles diffusion within the adjacent electrolyte. In scope of the third group of problems, the tested particles reactions on the electrodes covered with metal-containing polymer films are considered. As follows from the proper analysis, the current–voltage curves of these processes are described with the well-known equations of the electrochemical kinetics. Validity of the obtained conclusions is illustrated with the corresponding experimental results.