As in previous Olympics the men's competition was organized for "U23" players, footballers at most 23 years old, but three older players were allowed on each team. Prior to the Olympics, major discussion ensued when several European clubs would not release their players to compete in the Olympics. After a short summer holiday because of the European Championships, several teams had to compete in the preliminary rounds of the Champions League or UEFA Cup, and required their players to be present. The clubs argued the Olympic tournament was not on the official international calendar, and thus they were not required to release their players, as is common for international tournaments. The International Football Federation (FIFA) meanwhile announced that the tournament had been "informally" on the calendar for years, and clubs would have to oblige. Eventually, the case was taken to the Court of Arbitration for Sport (CAS), which decided in favour of the clubs. Eventually, most players did play in Beijing, although a few were forced to fly back to Europe before completion of the competition.

Two of the affected footballers were the star players of the South American favourites, [Lionel Messi] (Argentina) and [Ronaldinho] (Brazil). Both played for Spanish side FC Barcelona, which wanted the players to withdraw. However, Messi was eventually allowed to compete, while Ronaldinho completed a transfer to Italy just before the Olympics. Ronaldinho's Brazil was looking to finally win the Olympic gold medal that had eluded Brazil for decades, while Argentina was defending its 2004 title, and had won the 2005 and 2007 editions of the U20 World Cup. Other contenders were assumed to be the African sides of Cameroon (the 2000 Champions), Nigeria (gold in 1996) and Italy and the Netherlands from Europe.

Brazil and Argentina were the only teams to qualify for the quarter-finals undefeated. Both needed extra time to win their matches against Cameroon and the Netherlands, respectively, before clashing in the semi-finals. The match was highly anticipated, but turned out to be a fairly one-sided affair, with Argentina beating their neighbours 3-0. Two goals were scored by [Sergio Aguero], with his father-in-law (former star player Maradona) watching from the stands. In the other semi-final, Nigeria had little trouble with Belgium, the tournament's biggest surprise.

In the final, a replay of the 1996 Olympic final in Atlanta, Nigeria and Argentina were evenly matched in the first 45 minutes. In the 58th minute, a quick break from Argentina resulted in the match's only goal, as [Ángel di Maria] chipped the ball over the goalkeeper. Nigeria pressed hard in the final half hour, but were unable to pull of the same stunt as in 1996. Argentina thus became the first repeat winners of the Olympic title in 40 years, after Hungary won the title in 1964 and 1968.