Swimming was contested at the 1978 Asian Games in Kasetsart University, Bangkok, Thailand from December 12 to December 17, 1978.
Medalists
Men
Women
Medal table
| Rank | Nation | Gold | Silver | Bronze | Total |
|---|---|---|---|---|---|
| 1 |  Japan (JPN) | 25 | 17 | 5 | 47 |
| 2 |  Singapore (SIN) | 2 | 1 | 0 | 3 |
| 3 |  Philippines (PHI) | 1 | 0 | 3 | 4 |
 Thailand (THA) | 1 | 0 | 3 | 4 | |
| 5 |  China (CHN) | 0 | 8 | 6 | 14 |
| 6 |  Indonesia (INA) | 0 | 3 | 9 | 12 |
| 7 |  South Korea (KOR) | 0 | 0 | 3 | 3 |
| Totals (7 entries) | 29 | 29 | 29 | 87 | |
