The women's 400-metre individual medley event at the 2001 World Aquatic Championships took place 22 July. Both the heats and final were held on 22 July.

Records Prior to the competition, the existing world and championship records were as follows: World record 4:33.59 Sydney, Australia 16 September 2000Championship record 4:36.10 Guayaquil, Ecuador 1 August 1982

Results

Heats

Rank Swimmer Nation Time Notes 1 Beatrice Câșlaru 4:40.36 Q 2 Martha Bowen 4:41.31 Q 3 Nicole Hetzer 4:41.81 Q 4 Yana Klochkova 4:42.52 Q 5 Kaitlin Sandeno 4:43.88 Q 6 Qi Hui 4:44.65 Q 7 Tomoko Hagiwara 4:45.94 Q 8 Ayane Sato 4:46.05 Q 9 Jennifer Reilly 4:46.29 10 Hana Netrefová 4:47.46 11 Oxana Verevka 4:47.55 12 Paula Carballido 4:48.54 13 Sara Nordenstam 4:49.26 14 Simona Păduraru 4:49.45 15 Helen Nolfolr 4:50.60 16 Georgina Bardach 4:52.31 17 Miriana Bosevska 4:53.01 18 Megan McMahon 4:57.73 19 Wai Yen Sia 4:57.91 20 Lin Chi-Chan 5:04.79 21 Lára Hrund Bjargardóttir 5:09.31 22 Kuan Chia-Hsien 5:11.33

Final

Rank Name Nationality Time Notes Yana Klochkova 4:36.98 Martha Bowen 4:39.06 Beatrice Câșlaru 4:39.33 4 Qi Hui 4:41.64 5 Kaitlin Sandeno 4:43.13 6 Nicole Hetzer 4:44.77 7 Tomoko Hagiwara 4:48.47 – Ayane Sato DSQ

Key: WR = World record

References