Swimming was contested at the 1990 Asian Games in National Olympics Sports Center, Beijing, China from September 23 to September 28, 1990.

Event	Gold		Silver		Bronze
50 m freestyle details	Shen Jianqiang  China	22.99 GR	Ang Peng Siong  Singapore	23.33	Feng Qiangbiao  China	23.42
100 m freestyle details	Shen Jianqiang  China	50.64 GR	Xie Jun  China	51.02	Richard Sam Bera  Indonesia	51.79
200 m freestyle details	Xie Jun  China	1:51.90 GR	Tomohiro Noguchi  Japan	1:52.48	Wang Dali  China	1:52.56
400 m freestyle details	Tomohiro Noguchi  Japan	3:56.32 GR	Takafumi Asahara  Japan	3:58.85	Yan Yumin  China	4:00.00
1500 m freestyle details	Masayuki Fujimoto  Japan	15:43.24	Jeffrey Ong  Malaysia	15:46.90	Masashi Kato  Japan	15:49.71
100 m backstroke details	Lin Laijiu  China	57.47	Hajime Itoi  Japan	57.79	Keita Soraoka  Japan	57.82
200 m backstroke details	Ji Sang-jun  South Korea	2:03.59 GR	Keita Soraoka  Japan	2:03.88	Hajime Itoi  Japan	2:04.03
100 m breaststroke details	Chen Jianhong  China	1:02.60 GR	Kenji Watanabe  Japan	1:03.12	Nobuyuki Kawaguchi  Japan	1:03.25
200 m breaststroke details	Kenji Watanabe  Japan	2:17.49 GR	Nobuyuki Kawaguchi  Japan	2:19.84	Wirmandi Sugriat  Indonesia	2:20.06
100 m butterfly details	Shen Jianqiang  China	54.29 GR	Kunio Sugimoto  Japan	55.37	Tomohiro Miyoshi  Japan	56.33
200 m butterfly details	Kunio Sugimoto  Japan	2:00.25 GR	Tomohiro Miyoshi  Japan	2:00.50	Lee Yun-ahn  South Korea	2:01.23
200 m individual medley details	Takahiro Fujimoto  Japan	2:05.50	Shuichi Nakamura  Japan	2:05.95	Xie Jun  China	2:06.35
400 m individual medley details	Takahiro Fujimoto  Japan	4:26.10 GR	Shuichi Nakamura  Japan	4:30.79	Kim Seong-tae  South Korea	4:33.88
4 × 100 m freestyle relay details	China Xie Jun Feng Qiangbiao Wang Dali Shen Jianqiang	3:24.96 GR	Japan Masakatsu Usami Ken Nakazawa Hidetoshi Yamanaka Katsunori Fujiwara	3:27.69	Singapore Ang Peng Siong Harold Gan David Lim Kenneth Yeo	3:31.46
4 × 200 m freestyle relay details	Japan Hidetoshi Yamanaka Katsunori Fujiwara Takafumi Asahara Tomohiro Noguchi	7:30.34 GR	China Yan Yumin Wang Dali Chen Suwei Xie Jun	7:30.44	South Korea Ji Sang-jun Lim Cheol-seong Kwon Sang-won Lee Yun-ahn	7:46.83
4 × 100 m medley relay details	China Lin Laijiu Chen Jianhong Shen Jianqiang Xie Jun	3:45.18 GR	Japan Hajime Itoi Kenji Watanabe Kunio Sugimoto Katsunori Fujiwara	3:47.98	South Korea Ji Sang-jun Yun Ju-il Lee Yun-ahn Kim Dong-hyeon	3:54.73

Event	Gold		Silver		Bronze
50 m freestyle details	Yang Wenyi  China	25.86 GR	Sun Chunli  China	26.32	Naoko Imoto  Japan	26.45
100 m freestyle details	Zhuang Yong  China	55.30 GR	Wang Xiaohong  China	56.10	Suzu Chiba  Japan	57.06
200 m freestyle details	Zhuang Yong  China	2:01.43 GR	Suzu Chiba  Japan	2:02.27	Shen Xiaoyu  China	2:02.36
400 m freestyle details	Yan Ming  China	4:13.55 GR	Shen Xiaoyu  China	4:14.25	Suzu Chiba  Japan	4:20.93
800 m freestyle details	Yan Ming  China	8:40.27 GR	Shen Xiaoyu  China	8:42.01	Tomomi Hosoda  Japan	8:54.55
100 m backstroke details	Yang Wenyi  China	1:03.83 GR	Lin Li  China	1:03.85	Satomi Oguri  Japan	1:04.45
200 m backstroke details	Lin Li  China	2:13.81 GR	Wang Hui  China	2:16.66	Satomi Oguri  Japan	2:16.88
100 m breaststroke details	Huang Xiaomin  China	1:10.08 GR	Kyoko Kasuya  Japan	1:11.55	Asako Natsume  Japan	1:12.41
200 m breaststroke details	Lin Li  China	2:30.79 GR	Huang Xiaomin  China	2:31.02	Kyoko Kasuya  Japan	2:31.86
100 m butterfly details	Wang Xiaohong  China	58.87 GR	Qian Hong  China	58.89	Yoko Kando  Japan	1:01.73
200 m butterfly details	Wang Xiaohong  China	2:09.62 GR	Qian Hong  China	2:10.40	Rie Shito  Japan	2:13.98
200 m individual medley details	Lin Li  China	2:13.16 GR	Fumie Kurotori  Japan	2:19.66	Xia Fujie  China	2:22.06
400 m individual medley details	Lin Li  China	4:39.88 GR	Yan Ming  China	4:46.97	Fumie Kurotori  Japan	4:50.63
4 × 100 m freestyle relay details	China Zhuang Yong Qian Hong Wang Xiaohong Yang Wenyi	3:46.39 GR	South Korea Kim Eun-jeong Myeong Kyeong-hyeon Lee Moon-hee Lee Eun-ju	3:56.81	Indonesia Khim Tjia Fei Meitri Widya Pangestika Yen Yen Gunawan Elfira Rosa Nasution	3:59.54
4 × 100 m medley relay details	China Yang Wenyi Huang Xiaomin Wang Xiaohong Zhuang Yong	4:11.74 GR	Japan Satomi Oguri Kyoko Kasuya Yoko Kando Suzu Chiba	4:15.66	South Korea Lee Chang-ha Park Seong-won Yoo Hong-mi Kim Su-jin	4:25.50

Rank	Nation	Gold	Silver	Bronze	Total
1	China (CHN)	23	12	6	41
2	Japan (JPN)	7	16	16	39
3	South Korea (KOR)	1	1	5	7
4	Singapore (SIN)	0	1	1	2
5	Malaysia (MAL)	0	1	0	1
6	Indonesia (INA)	0	0	3	3
Totals (6 entries)		31	31	31	93

• New Straits Times, September 24–29, 1990
• Sports 123: Asian Games

• Olympic Council of Asia