288The main aspects of aluminum and aluminum alloys protection by corrosion coatings based on various forms of polyaniline (PAn) were considered in the presented chapter. The advantages and disadvantages of modern chemical and electrochemical methods of application of PAn protective coatings on aluminum-containing substrates were analyzed as well as the relationship between the conditions of application of protective layers and their protective properties was shown. The modern approaches to the use of PAn in protective corrosion coatings, such as doping by polymeric acids, the formation of double-strand PAn complexes, the use of PAn as the pigment filler in paint coating, as well as a major component of various polymer–polymer or polymer-inorganic hybrid composites were considered. Proposed today mechanisms of protective action of protonated and deprotonated forms of PAn were in detail analyzed concerning to the corrosion of aluminum-containing substrates by forming of the protective oxide or salt passivation layers, as well as the inhibition of redox processes by PAn doping anions was considered. A special attention has been paid into the negative role of the intermetallic surface inclusions concerning to the initiation of corrosion and to the use of conversion cerium coatings to eliminate of this problem.