Polyaniline (PANi) and poly(l,5-diaminonaphthalene) (PDAN) films can be deposited on iron from aqueous sulfuric acid. The films exhibit electroactive properties similar to those of PANi and PDAN generated on platinum. Electrosynthesis performed in the presence of both monomers leads to a composite him which presents excellent adhesion properties on iron. The composite film imparts a form of anodic protection for at least 9 days in pH 4 sulfate medium.