The knockout phase of the 2011–12 UEFA Champions League began on 14 February with the round of 16, and concluded on 19 May 2012 with the final at Allianz Arena in Munich, Germany.
All draws were held at UEFA headquarters in Nyon, Switzerland.
The team that had the higher aggregate score over the two legs progressed to the next round.
In the event that aggregate scores finished level, the away goals rule was applied, i.e. the team that scored more goals away from home over the two legs progressed.
If away goals were also equal, then thirty minutes of extra time were played, divided into two fifteen-minutes halves.
If no goals were scored during extra time, the tie was decided by a penalty shoot-out.
The final was played on 19 May 2012 at the Allianz Arena in Munich, Germany.