Electrolysis using a periodic current or potential in the forms of sinusoidal, triangular, and rectangular waves is common in pulse plating, AC corrosion, anodizing aluminium, and charging of secondary batteries. The periodic current/potential component causes the concentration of reacting ions to periodically fluctuate near the electrode surface, and thereby modify the polarization behavior of the electrode reaction. Previous investigations have shown that periodic current enhances the rate of electrode reaction and destroys the passivity of metals. This paper presents a review of the AC corrosion and pulse plating processes. The effect of periodic current on the mass transfer, electrokinetics, and current distribution is discussed.