| 1 | Rondell Bartholomew | GRN | 44,82 | Q | |
| 2 | Renny Quow | TRI | 44,84 | Q | |
| 3 | Greg Nixon | USA | 45,16 | Q | |
| 4 | Tabarie Henry | ISV | 45,22 | Q | |
| 5 | Riker Hylton | JAM | 45,54 | q | |
| 6 | Mathieu Gnanligo | BEN | 47,01 | ||
| 7 | Nelson Stone | PNG | 47,86 | ||
| 8 | Kerfalla Camara | GUI | 49,74 |
| 1 | Jermaine Gonzales | JAM | 45,12 | Q | |
| 2 | Jamaal Torrance | USA | 45,44 | Q | |
| 3 | Marcin Marciniszyn | POL | 45,51 | Q | |
| 4 | Demetrius Pinder | BAH | 45,53 | Q | |
| 5 | Erison Hurtault | DMA | 46,10 | q | |
| 6 | Nicolau Palanca | ANG | 49,37 | ||
| 7 | Ak. Hafiy Tajuddin Rositi | BRU | 50,12 |
| 1 | LaShawn Merritt | USA | 44,35 | Q | |
| 2 | Kévin Borlée | BEL | 44,77 | Q | |
| 3 | Rabah Yousif | SUD | 45,20 | Q | |
| 4 | Yuzo Kanemaru | JPN | 45,51 | Q | |
| 5 | Pavel Trenikhin | RUS | 45,55 | q | |
| 6 | Arnold Sorina | VAN | 48,76 | ||
| Gary Kikaya | COD | DNS | |||
| Arismendy Peguero | DOM | DNS |
| 1 | Kirani James | GRN | 45,12 | Q | |
| 2 | Jonathan Borlée | BEL | 45,16 | Q | |
| 3 | Ramon Miller | BAH | 45,31 | Q | |
| 4 | William Collazo | CUB | 45,89 | Q | |
| 5 | Bonggo Park | KOR | 46,42 | ||
| 6 | Pako Seribe | BOT | 46,97 | ||
| 7 | Augusto Stanley | PAR | 47,31 | ||
| 8 | Bahaa Al Farra | PLE | 49,04 | NR |
| 1 | Chris Brown | BAH | 45,29 | Q | |
| 2 | Martyn Rooney | GBR | 45,30 | Q | |
| 3 | Oscar Pistorius | RSA | 45,39 | Q | |
| 4 | Femi Ogunode | QAT | 45,42 | Q | |
| 5 | Nery Brenes | CRC | 45,47 | q | |
| 6 | Tony McQuay | USA | 46,76 | ||
| 7 | Ahmed Mohamed Al-Merjabi | OMA | 47,99 | ||
| Abdou Razack Rabo Samma | NIG | DQ |
| 1 | LaShawn Merritt | USA | 44,76 | Q | |
| 2 | Kévin Borlée | BEL | 45,02 | Q | |
| 3 | Rabah Yousif | SUD | 45,43 | ||
| 4 | Renny Quow | TRI | 45,72 | ||
| 5 | Ramon Miller | BAH | 45,88 | ||
| 6 | Yuzo Kanemaru | JPN | 46,11 | ||
| 7 | William Collazo | CUB | 46,13 | ||
| 8 | Erison Hurtault | DMA | 46,41 |
| 1 | Kirani James | GRN | 45,20 | Q | |
| 2 | Tabarie Henry | ISV | 45,53 | Q | |
| 3 | Chris Brown | BAH | 45,54 | ||
| 4 | Jamaal Torrance | USA | 45,73 | ||
| 5 | Nery Brenes | CRC | 45,93 | ||
| 6 | Marcin Marciniszyn | POL | 45,94 | ||
| 7 | Martyn Rooney | GBR | 46,09 | ||
| 8 | Riker Hylton | JAM | 46,99 |
| 1 | Jermaine Gonzales | JAM | 44,99 | Q | |
| 2 | Jonathan Borlée | BEL | 45,14 | Q | |
| 3 | Rondell Bartholomew | GRN | 45,17 | q | |
| 4 | Femi Ogunode | QAT | 45,41 | q | |
| 5 | Greg Nixon | USA | 45,51 | ||
| 6 | Pavel Trenikhin | RUS | 45,68 | ||
| 7 | Demetrius Pinder | BAH | 45,87 | ||
| 8 | Oscar Pistorius | RSA | 46,19 |