The top two countries in each group at the end of the stage qualified directly to the World Cup Finals in South Africa, with the two third-placed countries advancing to the AFC play-off.
Format
The 10 teams (2 teams from each group in the third round) were divided into four pots for the draw, three containing two teams and one containing four. The seeding for the fourth round was based on that used in the third round draw, but Saudi Arabia and Japan (seeded equal 4th in that draw) were separated by a random selection held at the start of the fourth round draw. The pots were as follows:
The 10 teams were split into two groups of five teams each – each containing one team from each of Pots 1, 2 and 3, as well as 2 teams from Pot 4.
The top two teams in each group qualified for the World Cup Finals, with the two third-placed sides advancing to a playoff. All teams played home and away against each of the other four teams in the group.
^Match played in Shanghai, China, as was the corresponding fixture in the Third round, as North Korea refused to play the anthem and fly the flag of South Korea.