| Order / Lane | Bib | ATHLETE | COUNTRY | PB | SB 2012 | 
|---|---|---|---|---|---|
| 2 | POL | Poland Junior |  POL | 39.31 | 39.31 | 
| 3 | AUS | Australia Junior |  AUS | 39.34 | 39.34 | 
| 4 | JPN | Japan Junior |  JPN | 39.01 | 39.01 | 
| 5 | JAM | Jamaica Junior |  JAM | 39.05 | 39.19 | 
| 6 | USA | United States Junior |  USA | 38.66 | 39.25 | 
| 7 | GBR | Great Britain & N.I. Junior |  GBR | 39.05 | 39.09 | 
| 8 | BAH | Bahamas Junior |  BAH | 39.48 | 39.48 | 
| 9 | BRA | Brazil Junior |  BRA | 39.29 | 39.29 |