The Men's 400 metres hurdles competition at the 1968 Summer Olympics in Mexico City, Mexico took place on October 13–15 at the Estadio Olímpico Universitario. In the final, David Hemery took the race out hard. By the final straightaway he had an ever growing lead over the world record holder Geoff Vanderstock. Hemery continued to pour it on, taking seven tenths of a second out of the world record, a huge improvement. Vanderstock struggled between the final barrier and the finish line, his 2 metre advantage over field evaporated. Gerhard Hennige, then John Sherwood edged past him at the line.