This article discusses corrosion and corrosion prevention, including surface preparation, conversion coating, and painting of aluminum and its alloys. It describes aluminum corrosion in terms of corrosion caused by high or low pH, pitting corrosion, crevice corrosion, galvanic corrosion, and filiform corrosion. The preparation of the surface of aluminum for pretreatments and coatings in coating facilities and in the field as well as the utilization of proper aluminum passivating surface treatments (conversion coatings) and corrosion-resistant organic coatings are discussed. The article provides information on the principal advantages and limitations of common coatings used for painting aluminum and on the organic coating specifications for use on aluminum extrusions and coil coating.