 In this review article, the fundamentals of electrochemical reactions involving metal hydrides are explained, followed by a report of recent progress in hydrogen storage alloys for electrochemical applications. The status of various alloy systems, including AB5, AB2, A2B7 type, TNI-based, MGNI-based, BCC, and ZRNI-based metal hydride alloys, for their most important electrochemical application, the nickel-metal hydride battery, is summarized. Other electrochemical applications, such as Ni-hydrogen, fuel cell, Li-ion battery, air-metal hydride, and hybrid battery systems, also have been mentioned. This article was authored by Kwosun Young and Jeanne Nguyen.