Bayer Leverkusen have lost the most games by a club in the Champions League in a season, with 9 losses in 2002-03.

	CLUB	L	SEASON	M	W	D	G	GC	XG	XGA	SH	SOT	PASS-ATT	PASS	POSS%	FOUL	YC	RC
1	Leverkusen	9	2002-03	12	3	0	14	26									23	0
2	Slovan Bratislava	8	2024-25	8	0	0	7	27	7.17	22.61	62	22	2,873	2,269	37.4	72	17	1
3	Young Boys	8	2024-25	8	0	0	3	24	5.69	19.75	81	18	2,876	2,322	41.7	116	24	0
4	Lokomotiv	8	2002-03	12	2	2	8	17									26	1
5	Girona	7	2024-25	8	1	0	5	13	9.98	12.75	79	31	3,774	3,282	51.1	116	25	1
6	Leipzig	7	2024-25	8	1	0	8	15	12.68	12.90	103	37	3,654	3,065	47.4	88	15	0
7	RB Salzburg	7	2024-25	8	1	0	5	27	6.81	19.69	75	22	3,631	3,054	45.1	92	16	1
8	Sturm Graz	6	2024-25	8	2	0	5	14	6.51	17.27	67	25	2,709	2,113	37.2	105	17	1
9	Sparta Prague	6	2024-25	8	1	1	7	21	6.52	13.57	75	21	2,552	1,928	33.2	81	13	0
10	Crvena Zvedza	6	2024-25	8	2	0	13	22	9.36	15.05	94	31	3,048	2,513	44.5	77	13	0
11	Plzen	6	2022-23	6	0	0	5	24	5.56	15.38	68	20	1,625	1,228	28.9	59	12	1
12	Rangers	6	2022-23	6	0	0	2	22	4.95	14.47	44	12	2,257	1,745	38.1	50	10	1
13	Besiktas	6	2021-22	6	0	0	3	19	5.20	17.95	49	12	2,474	1,981	44.3	63	0	0
14	AEK	6	2018-19	6	0	0	2	13			39	10	2,298	1,796	40.3	81	15	2
15	Benfica	6	2017-18	6	0	0	1	14			88	17	3,330	2,796	57.1	65	13	2
16	Club Brugge	6	2016-17	6	0	0	2	14			51	19	2,719	2,143	48.3	75	13	0
17	Dinamo	6	2016-17	6	0	0	0	15			36	14	1,949	1,440	31.5	65	13	1
18	Maccabi Tel Aviv	6	2015-16	6	0	0	1	16			51	12	2,325	1,885	41.2	80	14	1
19	Marseille	6	2013-14	6	0	0	5	14									15	1
20	Villarreal	6	2011-12	6	0	0	2	14									20	0
21	Dinamo	6	2011-12	6	0	0	3	22									18	1
22	Oțelul	6	2011-12	6	0	0	3	11									15	2
23	Žilina	6	2010-11	6	0	0	3	19									9	0
24	Partizan	6	2010-11	6	0	0	2	13									11	1
25	Maccabi Haifa	6	2009-10	6	0	0	0	8									13	2