Swimming at the 2009 World Aquatics Championships – Women's 400 metre individual medley explained

The heats and finals for the women's 400 m individual medley race at the 2009 World Championships took place in the morning and evening of 2 August at the Foro Italico in Rome, Italy. The order of swimming in the medley is: butterfly, backstroke, breaststroke, freestyle.

Records

Prior to this competition, the existing world and competition records were as follows:

World record		align=left	4:29.45	Beijing, China	10 August 2008
Championship record		align=left	4:32.89	Melbourne, Australia	1 April 2007

The following records were established during the competition:

Rank	Time	Heat	Lane	Notes
1	4:34.62	6	4
2	4:34.80	6	5
3	4:35.15	5	5
4	4:35.84	5	8	NR
4	4:35.84	6	3
6	4:36.27	4	4
7	4:36.42	5	4
8	4:37.47	6	6
9	4:37.84	6	1
10	4:38.20	5	1	NR
11	4:39.58	4	5
12	4:39.83	5	3
13	4:40.92	5	6
14	4:41.00	4	6
15	4:41.20	5	0
16	4:41.55	5	2
17	4:41.90	3	2
18	4:42.71	4	9	NR
19	4:42.96	6	8
20	4:43.20	3	4
21	4:43.77	4	8
22	4:43.87	4	2
23	4:45.13	3	5
24	4:46.31	4	1
25	4:46.57	6	9
26	4:46.93	5	7
27	4:47.11	4	7
28	4:48.87	5	9
29	4:49.74	6	0
30	4:50.53	3	0	NR
31	4:51.09	4	3
32	4:52.12	3	1
33	4:53.52	3	7
34	4:55.10	1	3
35	4:58.90	3	6
36	5:00.95	3	9
37	5:02.13	2	7
38	5:02.97	2	3
39	5:04.24	1	5
40	5:06.74	2	5
41	5:07.73	2	8
42	5:09.52	2	6
43	5:13.71	2	2
44	5:28.37	2	0
45	5:56.61	2	9
–	DNS	1	4
–	DNS	6	7
–	DQ	2	1
–	DQ	2	4
–	DQ	3	3
–	DQ	3	8
–	DQ	4	0
–	DQ	6	2