| 1 | Diane Dixon | USA | 52,12 | Q |
| 2 | Jillian Richardson | CAN | 52,17 | Q |
| 3 | Marie Holland | AUS | 52,21 | Q |
| 4 | Marina Charlamova | URS | 52,23 | |
| 5 | Charmaine Crooks | CAN | 52,52 | |
| 6 | Judit Forgacz | HUN | 53,86 |
| 1 | Helga Arendt | FRG | 52,29 | Q |
| 2 | Marina Shmonina | URS | 52,33 | Q |
| 3 | Sally Gunnell | GBR | 52,35 | Q |
| 4 | Iolanda Oanta | ROM | 52,93 | |
| 5 | Erzsebet Szabo | HUN | 52,93 | |
| 6 | Jearl Miles | USA | 53,28 |