This paper addresses the preparation and characterization of protective anticorrosion silane- and polyrhodanine-based bilayer coatings on a tested electrode substrate. Polyrhodanine (pRh) coatings were electrodeposited using the cyclic voltammetry technique on glassy carbon and stainless steel substrates. Isobutyltriethoxysilane (IBTES) films were deposited by the simple dip-coating method on steel substrates and then were stored in air ("aged"). The formed novel bilayer pRh/IBTES coatings were applied on the electrode surface as moderately thin (ca. 6-8 nm thick) layers and exhibited very good adhesion to the steel substrate. The physicochemical properties of pRh, IBTES and bilayer pRh/IBTES coatings were determined with the use of electrochemical, X-ray photoelectron spectroscopy and scanning electron microscopy techniques. The bilayer coatings consisting of a conducting polymer-pRh and silane-IBTES most effectively hinder the access of pitting-causing aggressive anions (chlorides) to the surface of stainless steel and exhibit better barrier properties compared to single-component pRh and IBTES coatings.