2006 AFC Champions League

The 2006 AFC Champions League was the 25th edition of the top-level Asian club football tournament and the fourth edition under the current AFC Champions League title. Al-Ittihad automatically qualified for the quarter-finals as the title holders.

Jeonbuk Hyundai Motors won their first AFC Champions League title after beating Al-Karamah 3–2 on aggregate in the final. Jeonbuk also became the first team in history of Asia to have won the Champions League before the national league title (they won their first K League championship three years later, in 2009).

Format
A total of 28 clubs were divided into seven groups of four, according to the region. Each club played double round-robin (home and away) against fellow three group members for a total of six matches. Clubs received three points for a win, one for a tie, and no points for a loss. The clubs were ranked according to points. If two or more teams were tied on points, the following tiebreaking criteria were applied:
 * Group stage
 * Points earned between the clubs in question
 * Goal difference between the clubs in question
 * Goals for between the clubs in question
 * Points earned within the group
 * Goal difference within the group
 * Goals for within the group

The seven group winners along with the defending champion advanced to the quarter-finals.

All 8 clubs were randomly matched; however, the only restriction was that the clubs from the same country could not face each other in the quarter-finals. The games were played over two legs, home and away, and the aggregate score decided the winner. If the aggregate score was level, the away goals rule was used. If still tied, clubs played extra time, where the away goals rule still applied. If still tied, the game went to penalties.
 * Knockout round

Teams

 * Notes

Second leg
Jeonbuk Hyundai Motors won 4–3 on aggregate.

Al Qadisiya won 5–2 on aggregate.

Ulsan Hyundai Horang-i won 7–0 on aggregate.

Al-Karamah won 4–2 on aggregate.

Second leg
Jeonbuk Hyundai Motors won 6–4 on aggregate.

Al-Karamah won 1–0 on aggregate.

Second leg
Jeonbuk Hyundai Motors won 3–2 on aggregate.

Top scorers
{{legend|silver|Team eliminated / inactive for this round.}}