Teams from twelve nations competed in the tournament and were seeded into two groups for the preliminary round. A total of 42 games were played, 30 of them in the preliminary round.
Format
The format of water polo at the 2012 Summer Olympics:[2]
Twelve teams were divided into two preliminary groups,[3] composed of six teams each, and played a single round robin in each group.
The top 4 teams from each group played against each other in a cross-group format in the Quarterfinals.
Winners from the Quarterfinal progressed to the Semifinals and played against another winner from the Quarterfinal round. Losers went on to play classification games.
Winners of the Semifinals contested the gold medal game and the losers the bronze medal game.