Nanolayers, prepared by Langmuir-Blodgett techniques, are potential replacements of currently applied surface inhibitors. Protective effects of octadecanoyl hydroxamic- and octadecyl phosphonic acid Langmuir-Blodgett films were studied in neutral sodium perchlorate solution. The protection efficiency of these monolayers on an Armco iron surface was characterized by electrochemical methods. Both types of nanolayers effectively decreased the corrosion processes at the metal surface. The difference between the efficiencies of the applied layers could be explained on the basis of interactions between their amphiphile head groups with the Armco iron surface. The size of the head group of octadecyl phosphonic acid is larger than that of octadecanoyl hydroxamic acid, which can be attributed to the better protective efficiency of octadecanoyl hydroxamic acids. (c) 2005 The Electrochemical Society.