1991 World Championships in Athletics – Women's 400 metres hurdles
These are the official results of the Women's 400 metres Hurdles event at the 1991 IAAF World Championships in Tokyo, Japan. There were a total number of 33 participating athletes, with five qualifying heats, two semi-finals and the final held on Thursday August 29, 1991.Schedule
Semi-Finals
| RANK | HEAT 1 | TIME |
| 1. | | 54.26 |
| 2. | | 54.44 |
| 3. | | 54.63 |
| 4. | | 54.77 |
| 5. | | 54.88 |
| 6. | | 55.36 |
| 7. | | 55.81 |
| 8. | | 56.62 |
| RANK | HEAT 2 | TIME |
| 1. | | 54.24 |
| 2. | | 54.36 |
| 3. | | 54.70 |
| 4. | | 55.22 |
| 5. | | 55.51 |
| 6. | | 55.66 |
| 7. | | 55.93 |
| 8. | | 56.17 |
Qualifying heats
| RANK | HEAT 1 | TIME |
| 1. | | 54.85 |
| 2. | | 54.94 |
| 3. | | 54.95 |
| 4. | | 55.60 |
| 5. | | 58.39 |
| 6. | | 58.80 |
| 7. | | 59.90 |
| RANK | HEAT 2 | TIME |
| 1. | | 54.53 |
| 2. | | 55.87 |
| 3. | | 56.16 |
| 4. | | 57.72 |
| 5. | | 58.05 |
| 6. | | 58.25 |
| RANK | HEAT 3 | TIME |
| 1. | | 54.70 |
| 2. | | 56.15 |
| 3. | | 56.37 |
| 4. | | 56.38 |
| 5. | | 57.55 |
| 6. | | 59.71 |
| 7. | | 1:00.45 |
| RANK | HEAT 4 | TIME |
| 1. | | 55.77 |
| 2. | | 55.77 |
| 3. | | 55.79 |
| 4. | | 57.13 |
| 5. | | 57.26 |
| 6. | | 1:01.49 |
| 7. | | 1:05.92 |
| RANK | HEAT 5 | TIME |
| 1. | | 55.81 |
| 2. | | 56.00 |
| 3. | | 56.35 |
| 4. | | 57.32 |
| 5. | | 57.81 |
| 6. | | 58.74 |
| 7. | | 59.00 |
