Corrosion inhibition of metals (iron, zinc, copper, tin, and aluminum, and, in particular, mild steel, and galvanized steel) is provided by treatment with an optionally substituted 2-hydroxy-5-alkylbenzaldoxime wherein the 5-alkyl group contains 7 to 13 atoms of carbon. The benzaldoxime may be applied directly, as a solvent solution or as an aqueous emulsion, or may be included in a surface coating composition. -- AATA