The influence of cationic surfactant benzethonium chloride (BCCS) on the corrosion resistance of 316L SS in MSF desalination plants during the scales removing by sulfuric acid solution has been studied. The investigations involved electrochemical polarization, weight loss, surface tension, conductivity, surface characterizations and quantum chemical studies. Results confirmed that the cationic surfactant plays a great role in retarding the corrosion 316L SS in 1.0 M H2SO4. The highest efficiency 92.3% is obtained at 3.5 x 10(-4) M of BCCS. The maximum inhibition efficiency is around the critical micelle concentration (CMC) of BCCS. Temkin isotherm describes by high precise the adsorption of BCCS on 316L SS. Polarization curves explained that BCCS is a mixed inhibitor. Theoretical quantum chemistry was utilized to support the effectiveness of BCCS compound.