The inhibition of pitting corrosion of stainless steel (SS) is addressed in this paper by using a new type of anticorrosive coatings consisting of Nafion (R)-polyaniline (PAn) composite films electrodeposited on stainless steel in a two-step process. The anticorrosive strategy presented here is based on the interfacial modification of SS with a Nafion (R) film, which as a cationic selective membrane prevents chloride ions to reach the SS surface. In addition, chloride insertion to the composite Nafion (R)-PAn film becomes less likely since sulfonate groups of the Nafion (R) contribute to the charge compensation of PAn and therefore charge transport processes involve proton expulsion than anion insertion. Nafion (R) films were pre-deposited at the surface of the SS electrode and the PAn films were formed on the SS vertical bar Nafion (R) electrode by cyclic voltammetry in 0.5 M H2SO4 solutions containing 0.1 M aniline. Open circuit potential and potentiodynamic measurements were used for the evaluation of the corrosion protection properties of the Nalion (R)-PAn composites. (c) 2005 Elsevier Ltd. All rights reserved.