Three paths for the iodine redox process at platinum electrodes are discussed with reference to stationary current/potential curves obtained for the cathodic reduction of the tri‐iodide ion in potassium iodide solutions. It is shown that the process follows the path originally proposed by Vetter, the slow stage being the transfer of an electron from the platinum to an adsorbed iodine atom, and that the degree of reversibility of the process increases as the concentration ratio of tri‐iodide to iodide is decreased. The apparent energy of activation for the over‐all process is 5.3 kcal·mole−1 for solutions containing only potassium iodide and tri‐iodide. The results, and those of other workers, indicate that the electrode surface is nonuniform.