The Colorado Rockies had the highest ERA by a team in 2004, with an ERA of 5.54.

	TEAM	ERA	SEASON	G	W%	W	L	GS	SO	CG	SHO	SV	IP	H	ER	R	HR	BB	HBP	IBB	TBF	WP	K/9	BB/9	K/BB	HR/9	K%	BB%	WHIP	BABIP	RA	H/9
1	Rockies	5.54	2004	162	.420	68	94	162	947	3	0	36	1435.1	1,634	883	923	198	697	71	84	6,535	66	5.94	4.37	1.36	1.24	14.5	10.7	1.62	.311	5.79	10.25
2	Reds	5.19	2004	162	.469	76	86	162	992	5	2	47	1443.2	1,595	832	907	236	572	54	55	6,451	74	6.18	3.57	1.73	1.47	15.4	8.9	1.50	.296	5.65	9.94
3	Royals	5.15	2004	162	.358	58	104	162	887	6	2	25	1420.1	1,638	813	905	208	518	56	49	6,320	60	5.62	3.28	1.71	1.32	14.0	8.2	1.52	.307	5.73	10.38
4	Diamondbacks	4.98	2004	162	.315	51	111	162	1,153	5	2	33	1436.0	1,480	794	899	197	668	75	79	6,418	71	7.23	4.19	1.73	1.23	18.0	10.4	1.50	.297	5.63	9.28
5	Tigers	4.93	2004	162	.444	72	90	162	995	7	4	35	1439.2	1,542	788	844	190	530	54	33	6,296	71	6.22	3.31	1.88	1.19	15.8	8.4	1.44	.299	5.28	9.64
6	White Sox	4.91	2004	162	.512	83	79	162	1,013	8	2	34	1432.1	1,505	782	831	224	527	48	36	6,189	43	6.37	3.31	1.92	1.41	16.4	8.5	1.42	.293	5.22	9.46
7	Blue Jays	4.91	2004	161	.416	67	94	161	956	6	4	37	1421.0	1,505	775	823	181	608	58	47	6,281	60	6.05	3.85	1.57	1.15	15.2	9.7	1.49	.296	5.21	9.53
8	Indians	4.81	2004	162	.494	80	82	162	1,115	8	3	32	1466.2	1,553	784	857	201	579	62	47	6,450	43	6.84	3.55	1.93	1.23	17.3	9.0	1.45	.301	5.26	9.53
9	Devil Rays	4.81	2004	161	.435	70	91	161	923	3	0	35	1417.0	1,459	757	842	192	580	93	35	6,261	55	5.86	3.68	1.59	1.22	14.7	9.3	1.44	.283	5.35	9.27
10	Mariners	4.76	2004	162	.389	63	99	162	1,036	7	2	28	1459.1	1,498	772	823	212	575	72	32	6,389	45	6.39	3.55	1.80	1.31	16.2	9.0	1.42	.286	5.08	9.24
11	Orioles	4.70	2004	162	.481	78	84	162	1,090	8	4	27	1455.1	1,488	760	830	159	687	62	43	6,459	68	6.74	4.25	1.59	0.98	16.9	10.6	1.49	.298	5.13	9.20
12	Yankees	4.69	2004	162	.623	101	61	162	1,058	1	0	59	1443.2	1,532	752	808	182	445	60	32	6,240	57	6.60	2.77	2.38	1.13	17.0	7.1	1.37	.300	5.04	9.55
13	Rangers	4.53	2004	162	.549	89	73	162	979	5	2	52	1439.2	1,536	724	794	182	547	81	29	6,345	34	6.12	3.42	1.79	1.14	15.4	8.6	1.45	.297	4.96	9.60
14	Phillies	4.45	2004	162	.531	86	76	162	1,070	4	4	43	1462.2	1,488	724	781	214	502	66	60	6,308	40	6.58	3.09	2.13	1.32	17.0	8.0	1.36	.286	4.81	9.16
15	Expos	4.33	2004	162	.414	67	95	162	1,032	11	4	31	1447.0	1,477	696	769	191	582	79	78	6,307	43	6.42	3.62	1.77	1.19	16.4	9.2	1.42	.291	4.78	9.19
16	Giants	4.29	2004	162	.562	91	71	162	1,020	8	5	46	1457.0	1,481	695	770	161	548	47	35	6,321	52	6.30	3.39	1.86	0.99	16.1	8.7	1.39	.290	4.76	9.15
17	Pirates	4.29	2004	161	.447	72	89	161	1,079	3	2	46	1428.0	1,451	680	744	149	576	63	64	6,197	45	6.80	3.63	1.87	0.94	17.4	9.3	1.42	.301	4.69	9.14
18	Angels	4.28	2004	162	.568	92	70	162	1,164	2	2	50	1454.1	1,476	692	734	170	502	44	27	6,246	61	7.20	3.11	2.32	1.05	18.6	8.0	1.36	.299	4.54	9.13
19	Brewers	4.24	2004	161	.416	67	94	161	1,098	6	1	42	1442.0	1,440	679	757	164	476	51	27	6,204	59	6.85	2.97	2.31	1.02	17.7	7.7	1.33	.289	4.72	8.99
20	Red Sox	4.18	2004	162	.605	98	64	162	1,132	4	1	36	1451.1	1,430	674	768	159	447	92	28	6,222	39	7.02	2.77	2.53	0.99	18.2	7.2	1.29	.289	4.76	8.87
21	Athletics	4.17	2004	162	.562	91	71	162	1,034	10	3	35	1471.1	1,466	682	742	164	544	68	49	6,313	39	6.32	3.33	1.90	1.00	16.4	8.6	1.37	.289	4.54	8.97
22	Marlins	4.10	2004	162	.512	83	79	162	1,116	6	3	53	1439.0	1,395	655	700	166	513	51	61	6,110	35	6.98	3.21	2.18	1.04	18.3	8.4	1.33	.288	4.38	8.72
23	Mets	4.09	2004	162	.438	71	91	162	977	2	2	31	1449.0	1,452	658	731	156	592	49	70	6,333	30	6.07	3.68	1.65	0.97	15.4	9.3	1.41	.284	4.54	9.02
24	Astros	4.05	2004	162	.568	92	70	162	1,282	2	2	47	1443.0	1,416	650	698	174	525	68	61	6,201	45	8.00	3.27	2.44	1.09	20.7	8.5	1.35	.299	4.35	8.83
25	Twins	4.03	2004	162	.568	92	70	162	1,123	4	4	48	1476.0	1,523	661	715	167	431	54	27	6,269	45	6.85	2.63	2.61	1.02	17.9	6.9	1.32	.302	4.36	9.29