The teams were drawn into twelve groups of four, and played each other home-and-away in a round-robin format. The matchdays were 15 September, 29 September, 20 October, 3 November, 30 November–1 December, and 14–15 December 2011.
Teams were seeded into four pots based on their 2011 UEFA club coefficients. Pot 1 held teams ranked 18–49, Pot 2 held teams ranked 51–85, Pot 3 held teams ranked 89–154, while Pot 4 held teams ranked 155–302 and unranked teams.
Notes
For the group stage draw, teams from the same national association could not be drawn against each other. Moreover, the draw was controlled for teams from the same association in order to split the teams evenly for maximum television coverage. For example, if there were two teams from the same association, each team was drawn into a different set of groups (A–F, G–L); if there were four teams from the same association, each team was drawn into a different subset of groups (A–C, D–F, G–I, J–L).
The fixtures were decided after the draw. On the first four matchdays, when matches were played only on Thursdays, six groups played their matches at 19:00 CET/CEST, while the other six groups played their matches at 21:05 CET/CEST, with the two sets of groups (A–F, G–L) alternating between each matchday. On the final two matchdays, when matches were played on both Wednesdays and Thursdays, the two sets of groups were divided into four smaller subsets (A–C, D–F, G–I, J–L), with each subset of groups playing on a different day and time. There are other restrictions, e.g., teams from the same city (e.g. Tottenham Hotspur and Fulham) do not play at home on the same matchday (UEFA tries to avoid teams from the same city play at home on the same day), and Russian teams do not play at home on the last matchday due to cold weather.
Tie-breaking criteria
If two or more teams were equal on points on completion of the group matches, the following criteria would be applied to determine the rankings:
higher number of points obtained in the group matches played among the teams in question;
superior goal difference from the group matches played among the teams in question;
higher number of goals scored in the group matches played among the teams in question;
higher number of goals scored away from home in the group matches played among the teams in question;
If, after applying criteria 1) to 4) to several teams, two teams still have an equal ranking, the criteria 1) to 4) will be reapplied to determine the ranking of these teams;
superior goal difference from all group matches played;
higher number of goals scored from all group matches played;
higher number of coefficient points accumulated by the club in question, as well as its association, over the previous five seasons.
Groups
Times up to 29 October 2011 (matchdays 1–3) are CEST (UTC+02:00), thereafter (matchdays 4–6) times are CET (UTC+01:00).
PAOK
Hannover 96
Hapoel Tel Aviv
Rapid București
Lazio
Stoke City
Beşiktaş
AZ
Austria Wien
Club Brugge
Atlético Madrid