Abstract: The electrochemical behavior of primers modified with polyaniline (PANI) and Cashew Nut Shell Liquid (CNSL) was evaluated by using Tafel polarization curves and Electrochemical Impedance Spectroscopy (EIS) in 0.1 M HCl solution. The measurements carried out suggest that primer modified with combined PANI and CNSL mixture were a good corrosion inhibitor. The high concentrations (5%) in both modifier was capable corrosion inhibitor with highest inhibition efficiency, however, the mixture of these was more efficient. This results were reasonably agreement by measurements obtained with Tafel polarization curves and electrochemical impedance spectroscopy. The combination of PANI and CNSL inhibitors considerably improves the anticorrosive properties of commercial primers.