A B S T R A C T Triazoles (Benzotriazole and Benzyl benzotriazole) were used as corrosion inhibitors for mild steel in hydrochloric acid solution. The inhibition efficiency depended on the concentration and type of the triazoles. The inhibition efficiency ranged between 80 and 98 % at the highest concentration (25 mM), and between 65 and 85% of the lowest concentration (5 mm) of inhibitor in 1 M HCl solution. Inhibition efficiency decreased with rise in temperature, this corresponded to surface coverage of the metal by the inhibitor. The calculated degrees of surface coverage, θ, were found to increase with the inhibitor concentration. The results also showed that, the inhibitors were adsorbed on the mild steel surface according to Langmuir and Temkin adsorption isotherm. Polarization study revealed that all the two triazole functioned as slightly anodic, but significantly cathodic inhibitors. K e y w o r d s Corrosion, Mild steel, Hydrochloric acid, Triazoles, Langmuir adsorption, Temkin's adsorption isotherm