Dutch swimmer Pieter van den Hoogenband defended his Olympic title in the event (the fourth man to do so), outside the record time of 48.17.

Roland Mark Schoeman, who solidified South Africa's triumph to break a world record in the 400 m freestyle relay, took home the silver in 48.23.

Other notable swimmers who missed the final cut featured France's Frédérick Bousquet, Lithuania's Rolandas Gimbutis, Trinidad and Tobago's George Bovell, and U.S. duo Jason Lezak and Ian Crocker.

Ian Thorpe of Australia, primarily a middle-distance swimmer who had not competed in the 100 in 2000 when he won five gold medals, had shown ability in sprinting by placing third in the 2003 world championship.

Azerbaijan, Burundi, Guyana, Iraq, Latvia, Pakistan, Papua New Guinea, and Serbia and Montenegro each made their debut in the event.