| Date | 18 October 1968 |
|---|---|
| Location | Alberca Olímpica Francisco Márquez, Ciudad de México |
| Pos | Lane | Competitor | NOC | Time | |||
|---|---|---|---|---|---|---|---|
| 1 | 5 | Sergey Gusev |  URS | 54.8 | |||
| 2 | 4 | Sandy Gilchrist |  CAN | 55.4 | |||
| 3 | 3 | Michele D'Oppido |  ITA | 57.3 | |||
| 4 | 6 | Gregorio Fiallo |  CUB | 58.2 | |||
| 5 | 7 | Geoffrey Ferreira |  TTO | 58.9 | |||
| 6 | 2 | Bob Loh |  HKG | 1:01.1 | |||
| – | Ingvar Eriksson |  SWE | – |
