The men's 400 metres hurdles was an event at the 1972 Summer Olympics in Munich. The competition was held on 31 August - 2 September. There were 37 competitors from 25 nations. The maximum number of athletes per nation had been set at 3 since the 1930 Olympic Congress. The event was won by John Akii-Bua of Uganda, the nation's first medal in the event and first gold medal in any Olympic event. Ralph Mann returned the United States to the podium after a one-Games absence with his silver medal, while David Hemery added a bronze to his 1968 gold to become the fifth man (and first non-American) to earn multiple medals in the event while extending Great Britain's podium streak in the 400 metres hurdles to three Games.