An experimental study has been made, using the potentiostat technique, of the anodic dissolution and electrolytic polishing of nickel in hydrochloric acid. The effect of experimental conditions on the potential/current density curves and the value of the limiting current density has been investigated. Results have been interpreted on the basis of a simple diffusion mechanism, and complications arising from the thick salt films found in the more concentrated solutions have been considered. Some results showing the connection between polishing and passivity have been collected for copper anodes in potassium cyanide solutions containing potassium hydroxide.