The anodic behaviour of various nickel-base materials has been examined at 90°C using simple acids in the presence of varying levels of lead. Lead, injected at potentials above the Pb++/Pb equilibrium, inhibited active dissolution of Ni due to underpotential deposition, a new observation. The inhibition is higher and happens over a wider range of potentials in the more acidic condition. Activation of Ni results on a surface that is trying to term its pre-passive film but is partly covered by Pb. The Cr content of Alloy 600 is insufficient to eliminate the lead effect, and evidence of nickel-like behaviour is present for this alloy. The presence of 21% Cr suppresses active dissolution, and eliminates, for these particular conditions, both the inhibiting and the activating effects of Pb. The relevance of these results to corrosion and SCC caused by lead in nuclear power systems is briefly discussed.