This work deals with the effect of nitrite ions on the breakdown of passive films formed on steel in simulating pore concrete solutions with a high content in carbonate ions. The solutions contain 0.015 mol l− 1 Na 2 CO 3 and 0.3 mol l− 1 NaHCO 3 and may incorporate 0.05 or 0.1 mol l− 1 NaCl. The inhibition efficiency is evaluated recording cyclic voltammograms, polarization curves, polarization resistance, impedance and Raman spectra. Weight-loss measurements were also performed. High CO 3− 2 concentrations favor the development of a passive film that becomes more compact when nitrite ions are added. As the [NO 2−]/[Cl−] increases, the films become more resistant to pitting attack. A linear relationship was established between E pit and log ([NO 2−]*([HCO 3−]+[CO 3=])/[Cl−]). It is shown that the [NO 2−]/[Cl−] ratio cannot be taken as an appropriate parameter to evaluate the inhibitor efficiency for different pH values and different carbonate and chloride ions concentrations. Instead, the results showed that exceeding [NO 2−]= 0.2 mol l− 1 can be taken as a better criterion for the level needed for adequate protection in the various electrolytes studied.