The men's decathlon competition at the 2004 Summer Olympics in Athens was held at the Olympic Stadium on 23–24 August.

[1] The decathlon consists of ten track and field events, with a points system that awards higher scores for better results in each of the ten components.

The athletes all compete in one competition with no elimination rounds.

At the end of competition, if two athletes are tied, the athlete who has received more points in the greater number of events is the winner.

[2] All times are Greece Standard Time (UTC+2) Prior to the competition[update], the existing World and Olympic records were as follows.