The effect of Achillea fragrantissima on the corrosion of zinc in 0.5 M HCl has been studied using weight loss, hydrogen evolution and polarization measurements. The inhibition efficiency was found to increase with increasing concentration and decrease with increasing temperature. Inhibition effect was explained on the basis of adsorption of Achillea fragrantissima components on the metal surface through the active centers contained in their structures. It was found also that adsorption of Achillea fragrantissima on zinc surface follows Langmuir adsorption isotherm. Thermodynamic and kinetic parameters for zinc corrosion and inhibition processes were calculated and interpreted.