However, when the Olympics returned in 1920 after World War I, the men's 400 metres hurdles was back and would continue to be contested at every Games thereafter.

The favorite was Roy Cochran of the United States, the world record holder in the 440 yards version of the event.

[1] Ceylon, the Republic of China, Colombia, New Zealand, Pakistan, Switzerland, and Turkey each made their debut in the event.

The United States made its ninth appearance, the only nation to have competed at every edition of the event to that point.

Rune Larsson improved the Olympic Record by a tenth of a second in the first semi-final, chased by Dick Ault and Duncan White.

With qualification exclusively based on place, Jean-Claude Arifon ran a full second faster than Ottavio Missoni but was fourth in the fast first semi and had to watch the final.

With the lead, Cochran continued to expand the gap, taking the tenth hurdle cautiously then pulling away to the finish.