The influence of the concentration of sodium succinate (SS) on the corrosion and spontaneous dissolution of copper in aerated non-stirred highly concentrated (5.0 M) NaCl solutions was studied at different temperatures (1060 degrees C. The investigations involved weight loss as well as potentiodynamic polarization and impedance measurements. The inhibition efficiency increases with increase in the concentration of SS and decreases with temperature. The inhibition mechanism involves adsorption of SS on the copper surface. An adherent layer of inhibitor is postulated to account for the protective effect. Energy dispersion X-ray (EDX) examinations of the electrode surface confirmed the existence of such an adsorbed film. The potential of zero charge (pzc) of copper was studied by the ac impedance technique and the mechanism of adsorption is discussed.