The inhibition effect of imidazole on the corrosion of mild steel in acid medium has been studied by mass loss and polarization techniques between 303 K and 333K. The inhibtion efficiency increased with increase in concentration of inhibitor and temperature from 303 K to 318 K for both acids. But higher temperature at 333K the inhibition efficiency decreased. The corrosion rate increases with increase in temperature and decreases with increase in concentration of inhibitor compare to blank. The adsorption of this compound on the mild steel surface has been found to obey Temkin's adsorption isotherm. Potentiostatic polarization results reveal that imidazole is a mixed type inhibitor. The values of activation energy (Ea) and free energy of adsorption (DG ads) were also calculated.