The effect of dichromate, chromate, molybdate, nitrite and nitrate anions on the chloride pitting corrosion of tin in each of the following solutions : Na2CO3 (pH = 10.9), Na2B4O7 (pH = 8.35) and Na2SO4 (pH = 6.8) (each solution containing 0.1 M NaCl) has been studied. The potentiodynamic technique was used, complemented by X-ray and SEM. Addition of increasing concentrations Cr2O72-, CrO42- or MoO42- caused a shift of the pitting potential (E(pit)) in the positive direction indicating the inhibitive effect of the added anions on the pitting corrosion. The absorption characteristics of these anions on the metal surface plays a significant role in inhibition. The NO2- anion has a little inhibitive effect of pitting corrosion but the NO3- anion is ineffective as an inhibitor, and actually increases pitting corrosion. The pitting corrosion of chloride ions and other aggressive anions in the solutions is completely suppressed at concentration greater than or equal to 0.01 M sodium dichromate. The MoO4- species limits the growth of the passive film, restricts Cl- anions and inhibits the pitting corrosion.