| POS | Rank | Heat | BIB | ATHLETE | COUNTRY | RESULTS |
|---|---|---|---|---|---|---|
| 1 | 1 | 3 | 27 | Tonique Williams-Darling |
BAH |
49.69 Q SB |
| 2 | 1 | 1 | 819 | Sanya Richards-Ross |
USA |
50.05 Q |
| 3 | 2 | 3 | 493 | Ana Guevara |
MEX |
50.33 Q |
| 4 | 1 | 2 | 653 | Svetlana Pospelova |
RUS |
50.34 Q |
| 5 | 2 | 2 | 834 | Deedee Trotter |
USA |
50.73 Q |
| 6 | 3 | 3 | 657 | Olesya Zykina |
RUS |
50.73 q SB |
| 7 | 4 | 3 | 799 | Monique Henderson |
USA |
50.73 q |
| 8 | 2 | 1 | 684 | Amy Mbacke Thiam |
SEN |
50.83 Q SB |
| 9 | 5 | 3 | 48 | Ilona Usovich |
BLR |
50.96 PB |
| 10 | 3 | 1 | 615 | Natalya Antyukh |
RUS |
50.99 |
| 11 | 3 | 2 | 18 | Christine Amertil |
BAH |
51.03 |
| 12 | 6 | 3 | 274 | Lee McConnell |
GBR |
51.15 SB |
| 13 | 4 | 2 | 277 | Christine Ohuruogu |
GBR |
51.43 |
| 14 | 5 | 2 | 401 | Lorraine Fenton |
JAM |
51.48 |
| 15 | 4 | 1 | 696 | Nawal El Jack |
SUD |
51.85 |
| 16 | 5 | 1 | 686 | Tiandra Ponteen |
SKN |
51.88 |
| 17 | 7 | 3 | 71 | Lucimar Teodoro |
BRA |
51.98 |
| 18 | 6 | 2 | 106 | Kaltouma Nadjina |
CHA |
52.07 |
| 19 | 8 | 3 | 364 | Karen Shinkins |
IRL |
52.17 |
| 20 | 7 | 2 | 680 | Fatou Bintou Fall |
SEN |
52.35 |
| 21 | 6 | 1 | 413 | Shericka Williams |
JAM |
52.44 |
| 22 | 8 | 2 | 548 | Anna Guzowska |
POL |
52.45 |
| 23 | 7 | 1 | 266 | Donna Fraser |
GBR |
52.48 |
| 24 | 8 | 1 | 45 | Anna Kozak |
BLR |
52.73 |