Development of the Mi-4 began in the early 1950s, after the Soviets noticed the success of American helicopters deployed during the Korean War. It was designed as a larger and more powerful H-19 Chickasaw. The first flight occurred on 3 June 1952, with the aircraft entering service the following year. The Mi-4 proved to be highly adaptable, seeing use by a number of militaries in a variety of roles in addition to transport, such as close-air support, anti-submarine warfare, and aerial fire fighting. Production ended in 1979 after around 4,500 were built. It was also license-built in China as the Harbin Z-5.