| POS | Rank | Heat | BIB | ATHLETE | COUNTRY | RESULTS | ms* |
|---|---|---|---|---|---|---|---|
| 1 | 1 | 2 | JAM | Jamaica |
JAM |
42.11 Q SB | |
| 2 | 2 | 2 | GBR | Great Britain & NI |
GBR |
42.25 Q SB | |
| 3 | 3 | 2 | CHN | PR of China |
CHN |
42.36 Q | |
| 4 | 1 | 1 | USA | United States |
USA |
42.46 Q | |
| 5 | 2 | 1 | TTO | Trinidad and Tobago |
TTO |
42.75 Q SB | |
| 6 | 3 | 1 | SUI | Switzerland |
SUI |
42.82 Q | .811 |
| 7 | 4 | 2 | GER | Germany |
GER |
42.82 q | .817 |
| 8 | 5 | 2 | ITA | Italy |
ITA |
42.90 q NR | |
| 9 | 4 | 1 | NED | Netherlands |
NED |
43.01 | |
| 10 | 6 | 2 | NGR | Nigeria |
NGR |
43.05 SB | |
| 11 | 7 | 2 | GHA | Ghana |
GHA |
43.62 SB | |
| 12 | 5 | 1 | KAZ | Kazakhstan |
KAZ |
43.79 | |
| 13 | 6 | 1 | DEN | Denmark |
DEN |
43.92 | |
| 1 | AUS | Australia |
AUS |
DNF | |||
| 2 | BRA | Brazil |
BRA |
DQ | |||
| 1 | FRA | France |
FRA |
DQ |
ms - Milliseconds - shown when two or more competitors finish with the same time down to hundredths of a second