| 1 | Bershawn Jackson | USA | 46,13 | Q | |
| 2 | David Gillick | IRL | 46,15 | Q | |
| 3 | William Collazo | CUB | 46,34 | Q | |
| 4 | Edino Steele | JAM | 46,84 | ||
| 5 | Michael Mathieu | BAH | 47,09 | ||
| 6 | Denis Alekseyev | RUS | 47,22 |
| 1 | Chris Brown | BAH | 46,64 | Q | |
| 2 | Jamaal Torrance | USA | 46,69 | Q | |
| 3 | Nery Brenes | CRC | 46,73 | Q | |
| 4 | Dmitry Buryak | RUS | 46,95 | ||
| 5 | Richard Buck | GBR | 47,70 | ||
| 6 | Ricardo Chambers | JAM | 48,02 |