A phosphomolybdic acid doped polyaniline (PANI) anti-corrosive coating was synthesized on stainless steel (304SS) by electropolymerization. The combination of phosphoric acid de-doping and phosphomolybdic acid re-doping processes leads to the direct and quick deposition of PANI-coating on 304SS without any residual oxidant impurities. The corrosion resistance of the coating was evaluated in 1 M I-12 SO4 solution by electrochemical techniques. The doping of phosphomolybdic acid enhances the corrosion resistance provided by the coating. The phosphomolybdic acid re-doped coating has a high Rt of 1999 SZ cm2 in comparison with the phosphoric acid doped and re-doped coatings. The increase in corrosion resistance is due to the presence of phosphomolybdic acid that promotes the formation of oxides which not only fill the pores in the PANI coating but also forms an interfacial oxide layer and hence block the corrosion of 304SS in acidic medium. (C) 2015 Elsevier B.V. All rights reserved.