Corrosion inhibition of Eruca sativa leaves extract on C-steel in 0.1 M H2SO4 was examined by weight loss and electrochemical techniques. It was found that the extract act as a good corrosion inhibitor for the tested system. The inhibition efficiency increases with increasing extract concentration and decreases with increasing temperature. The adsorption of inhibitor on the C-steel surface obeyed Langmuir adsorption isotherm. The calculated adsorption thermodynamic parameters indicated that the adsorption was spontaneous and .