| 1 | Devon Morris | JAM | 46,30 | Q |
| 2 | Charles Jenkins | USA | 46,55 | Q |
| 3 | Cayetano Cornet | ESP | 46,69 | Q |
| 4 | Abdelali Kasbane | MAR | 47,05 | |
| 5 | Mark Garner | AUS | 47,06 | |
| 6 | Ian Morris | TRI | DNF |
| 1 | Samson Kitur | KEN | 46,43 | Q |
| 2 | Howard Burnett | JAM | 46,62 | Q |
| 3 | Alvin Daniel | TRI | 47,03 | Q |
| 4 | Paule Greene | AUS | 47,?? | |
| 5 | Raymond Pierre | USA | 47,51 | |
| 6 | Antonio Sanchez | ESP | 47,59 |