The inhibitor effect of benzoic acid and salicylic acid in sulfuric acid medium on the steel with known composition has been investigated. It has been determined that the corrosion rates decrease and that percentage inhibition efficiencies and surface coverage degrees increase with increasing acid concentration in all cases. However, benzoic acid acts as a better inhibitor compared to salicylic acid with equal concentration. It has been determined that the adsorption for both organic acids on the steel complies with the Langmuir isotherm. (C) 2002 Elsevier Science B.V. All rights reserved.