| Event: | Water polo |
| Games: | 1978 Asian Games |
| Venue: | Kasetsart University |
| Dates: | 12–17 December 1978 |
| Nations: | 7 |
| Prev: | 1974 |
| Next: | 1982 |
Water polo was contested for men only at the 1978 Asian Games in Kasetsart University, Bangkok, Thailand from 12 December 1978 to 17 December 1978.
Seven countries participated in the men's competition, China won the gold medal in the round robin competition, Japan and Singapore finished second and third behind China.
| Men | Cai Shengliu Cai Tianxiong Li Jianming Liao Yiping Lu Zhouqian Peng Bailing Qu Baowei Wang Jianguang Wang Xiaotian Xu Lisan Zhang Huaguang | Akira Hara Hiroshi Hasegawa Kouji Hasegawa Tadashi Kotani Kunihiro Makihashi Mamaru Matani Masahiro Miyahara Toshiyuki Miyahara Masayuki Nagano Hisao Oyamatsu Kazuo Urushibara | Ang Ban Gee Ang Ban Leong Ang Guan Hin Stephen Chong Gan Ai Teck Kenneth Kee Michael Kong Lionel Liew Soh Seng Thit Teo Keng Soon Teo Ming Chun |
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| width=40 | Rank | width=180 | Team | width=30 | width=30 | width=30 | width=30 | ||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| 6 | 6 | 0 | 0 | ||||||||
| 6 | 5 | 0 | 1 | ||||||||
| 6 | 4 | 0 | 2 | ||||||||
| 4 | 6 | 3 | 0 | 3 | |||||||
| 5 | 6 | 2 | 0 | 4 | |||||||
| 6 | 6 | 1 | 0 | 5 | |||||||
| 7 | 6 | 0 | 0 | 6 |