Successful attempts to prepare compact and excellent adherent films of polyaniline (PAni) from phosphate buffered solutions on stainless steel are reported. Chemically synthesized PAni applied by coating from NMP-solution is compared to the electrochemically deposited one prepared by cyclic voltammetry. A systematic study of the corrosion inhibiting action of PAni in 3% NaCl solution shows a beneficial effect on protection in its doped state where the redox process controls the surface reaction. In undoped form PAni acts as a simple barrier film.