The effect of a new class of corrosion inhibitors, namely, Arylazobenzoyl acetonitrile derivatives, on the corrosion of carbon steel in 2 M HCl and 1 M H2SO4 solutions has been studied by electrochemical polarisation methods (potentiodynamic, Tafel extrapolation and the determination of polarisation resistance). Generally, inhibition efficiency of the investigated compounds was found to increases with increasing concentration. Results obtained from both potentiodynamic and polarisation resistance techniques reveal that these compounds are good inhibitors and behave better in 2 M HCl than 1 M H2SO4. The adsorption of the compounds on the carbon steel in both acidic media follows a Langmuir adsorption isotherm. (C) 2002 Elsevier Science B.V. All rights reserved.