Event Format: The 100 m race was run in straight lanes on the homestretch in the Stadium. Runners competed in preliminary heats, round one, semifinals and final. The best athletes from each heat (Q) and a number of "lucky losers" (q) advanced to the next level. A number of non pre-qualified runners participated in the preliminary heats. In round one all pre-qualified runners entered the competition.
Event facts: Men's 100 m competition was held at the Joao Havelange Olympic Stadium and 84 athletes participated in the event.