| Final 20:20 | time | | | 1. Japan | JPN | 4:00.94 | | | Shiho Sakai | 1:01.70 | | Kanako Watanabe | 1:06.79 | | Miyu Nakano | 58.80s | | Miki Uchida | 53.65s | | 2. South Korea | KOR | 4:04.82 | | | Lee Da-lin | 1:02.64 | | Yang Ji-won | 1:08.93 | | An Se-hyeon | 57.79s | | Ko Mi-so | 55.46s | | 3. Hong Kong | HKG | 4:07.15 | | | Stephanie Au | 1:01.96 | | Yvette Kong | 1:10.69 | | Sze Hang Yu | 1:00.08 | | Siobhan Haughey | 54.42s | | 4. Singapore | SGP | 4:11.77 | | | Tao Li | 1:03.42 | | Samantha Yeo | 1:11.93 | | Quah Ting Wen | 1:00.31 | | Amanda Lim | 56.11s | | 7. Thailand | THA | 4:16.66 | | | Natthanan Junkrajang | 1:05.57 | | Phiangkhwan Pawapotako | 1:12.11 | | Sarisa Suwannachet | 1:00.90 | | Benjaporn Sriphanomthorn | 58.08s | | 6. Chinese Taipei | TPE | 4:19.92 | | | Hsu An | 1:04.36 | | Lin Pei-wun | 1:12.58 | | Yu Yi-chen | 1:04.56 | | Yang Chin-kuei | 58.42s | | 7. Macau | MAC | 4:26.18 | | | Erica Vong | 1:05.36 | | Lei On Kei | 1:14.78 | | Ma Cheok Mei | 1:07.58 | | Tan Chi Yan | 58.46s | | 8. Mongolia | MGL | 5:07.23 | | | Bayaryn Yesüi | 1:18.96 | | Saintöriin Nomun | 1:26.03 | | Tsogtgereliin Möngönsor | 1:10.17 | | Enkhmandakhyn Nandinzayaa | 1:12.07 |
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| Venue: Muhak Park Tae-hwan Aquatics Center. | | South Korea originally won the bronze medal, but was later disqualified after Park Tae-hwan tested positive for Nebido. |
| World record: United States 3:08.24 Beijing, China 11 August 2008 | | Asian record: Japan 3:14.73 Hong Kong 8 December 2009 | | Games record: China 3:16.34 Guangzhou, China 16 November 2010 |
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