| Date | 18 October 1968 |
|---|---|
| Location | Alberca Olímpica Francisco Márquez, Ciudad de México |
| Pos | Lane | Competitor | NOC | Time | |||
|---|---|---|---|---|---|---|---|
| 1 | 4 | Zac Zorn |  USA | 53.4 | |||
| 2 | 5 | Luis Nicolao |  ARG | 53.8 | |||
| 3 | 1 | Ken Walsh | USA | 53.9 | |||
| 4 | 6 | Wolfgang Kremer |  FRG | 54.3 | |||
| 5 | 2 | Lester Eriksson |  SWE | 54.9 | |||
| 6 | 3 | José Antonio Chicoy |  ESP | 54.9 | |||
| 7 | 7 | François Simons |  BEL | 55.3 | |||
| 8 | 8 | Roosevelt Abdulgafur |  PHI | 55.9 |
