The men's 400 metres event at the 1987 European Athletics Indoor Championships was held on 21 and 22 February.[1]
| width=200 bgcolor=gold | Gold | width=200 bgcolor=silver | Silver | width=200 bgcolor=CC9966 | Bronze |
| Todd Bennett | Momchil Kharizanov Bulgaria | Paul Harmsworth |
| Rank | Heat | Name | Nationality | Time | Notes | |
|---|---|---|---|---|---|---|
| 1 | 1 | 47.01 | ||||
| 2 | 1 | 47.23 | ||||
| 3 | 1 | 47.39 | ||||
| 4 | 1 | 47.64 | ||||
| 5 | 1 | 47.75 | ||||
| 1 | 2 | 47.04 | ||||
| 2 | 2 | 47.16 | ||||
| 3 | 2 | 47.36 | ||||
| 4 | 2 | 47.68 | ||||
| 2 | ||||||
| 1 | 3 | 47.84 | ||||
| 2 | 3 | 47.86 | ||||
| 3 | 3 | 47.87 | ||||
| 4 | 3 | 48.04 | ||||
| 5 | 3 | 48.54 | ||||
| 1 | 4 | 47.28 | ||||
| 2 | 4 | 47.32 | ||||
| 3 | 4 | 47.39 | ||||
| 4 | 4 | 47.83 | ||||
| 5 | 4 | 49.14 | NR |
First 3 from each semifinal qualified directly (Q) for the final.
| Rank | Heat | Name | Nationality | Time | Notes | |
|---|---|---|---|---|---|---|
| 1 | 2 | 46.80 | Q | |||
| 2 | 2 | 46.87 | Q | |||
| 3 | 2 | 47.03 | Q | |||
| 4 | 1 | 47.09 | Q | |||
| 5 | 2 | 47.13 | ||||
| 6 | 1 | 47.52 | Q | |||
| 7 | 1 | 47.56 | Q | |||
| 8 | 2 | 47.63 | ||||
| 8 | 1 | 47.65 | ||||
| 10 | 2 | 47.79 | ||||
| 11 | 1 | 48.09 | ||||
| 12 | 1 | 48.15 |
| Rank | Name | Nationality | Time | Notes | |
|---|---|---|---|---|---|
| 46.81 | |||||
| 46.89 | |||||
| 46.92 | |||||
| 4 | 46.96 | ||||
| 5 | 47.42 | ||||
| 6 | 47.50 |