| POS | Rank | Heat | BIB | ATHLETE | COUNTRY | RESULTS | 
|---|---|---|---|---|---|---|
| 1 | 1 | 1 | 3044 | Lalonde Gordon |  TTO | 44.58 Q PB | 
| 2 | 1 | 2 | 2005 | Kirani JAMES |  GRN | 44.59 Q SB | 
| 3 | 2 | 2 | 1100 | Chris Brown |  BAH | 44.67 Q SB | 
| 4 | 1 | 3 | 1564 | Luguelín SANTOS |  DOM | 44.78 Q | 
| 5 | 2 | 3 | 1133 | Kévin BORLÉE |  BEL | 44.84 Q | 
| 6 | 2 | 1 | 1108 | Demetrius Pinder |  BAH | 44.94 Q | 
| 7 | 3 | 1 | 1060 | Steven SOLOMON |  AUS | 44.97 q PB | 
| 8 | 3 | 2 | 1132 | Jonathan BORLÉE |  BEL | 44.99 q | 
| 9 | 3 | 3 | 3241 | Bryshon Nellum |  USA | 45.02 | 
| 10 | 4 | 3 | 1105 | Ramon Miller |  BAH | 45.11 | 
| 11 | 4 | 1 | 2968 | Rabah YOUSIF |  SUD | 45.13 =PB | 
| 12 | 5 | 1 | 1519 | Pavel MASLÁK |  CZE | 45.15 | 
| 13 | 6 | 1 | 2124 | Tabarie Henry |  ISV | 45.19 SB | 
| 14 | 4 | 2 | 3235 | Tony MCQUAY |  USA | 45.31 | 
| 14 | 5 | 3 | 1831 | Martyn ROONEY |  GBR | 45.31 | 
| 16 | 7 | 1 | 2835 | Pavel Trenikhin |  RUS | 45.35 | 
| 17 | 8 | 1 | 1842 | Conrad Williams |  GBR | 45.53 | 
| 18 | 6 | 3 | 2177 | Dane Hyatt |  JAM | 45.59 | 
| 19 | 5 | 2 | 1816 | Nigel Levine |  GBR | 45.64 | 
| 20 | 7 | 3 | 2374 | Youssef Ahmed MASRAHI |  KSA | 45.91 | 
| 21 | 6 | 2 | 3345 | Alberth Bravo |  VEN | 46.22 | 
| 22 | 7 | 2 | 2790 | Oscar Pistorius |  RSA | 46.54 | 
| 23 | 8 | 3 | 2078 | Liemarvin BONEVACIA |  IOA | 1:36.42 | 
| 2 | 2806 | Maksim Dyldin |  RUS | DQ |