The kinetics of the Ni electrode in acid solutions with a high chloride ion concentration has been investigated in the range of 25–75°C. Dissolution occurs uniformly only at low anodic potentials. When the latter exceeds a critical value, Ecrit, net localized metal corrosion takes place. The plot at E < Ecrit corresponds to a curve approaching two limiting slopes, namely, at (. The cathodic Tafel slope is . These results, including their pH dependence, are explained with a reaction mechanism involving the participation of adsorbed hydroxo-species.