The 2008–09 CONCACAF Champions League championship round began on 24 February 2009.
The order of the home and away matches for the semifinals and finals were determined in the draw.
If the two teams are also tied in away goals, then two fifteen-minute halves of extra time are played.
If the two teams are still tied in total goals after extra time, a penalty shootout determines the winner.
The second leg was originally scheduled for 29 April, but was postponed until 12 May by CONCACAF due to concerns over an outbreak of swine flu in Mexico.