The men's 400 metres hurdles event at the 1992 World Junior Championships in Athletics was held in Seoul, Korea, at Olympic Stadium on 16, 17 and 18 September.
| Gold | Ashraf Saber | |
| Silver | Sammy Biwott | |
| Bronze | William Porter |
18 September
| Rank | Name | Nationality | Time | Notes | |||
|---|---|---|---|---|---|---|---|
| align=left | align=left | | 50.02 | ||||
| align=left | align=left | | 50.75 | ||||
| align=left | align=left | | 51.37 | ||||
| 4 | align=left | align=left | 51.50 | ||||
| 5 | align=left | align=left | 51.73 | ||||
| 6 | align=left | align=left | 51.85 | ||||
| 7 | align=left | align=left |  | 52.05 | |||
| 8 | align=left | align=left |  | 53.45 |
17 September
| Rank | Name | Nationality | Time | Notes | |||
|---|---|---|---|---|---|---|---|
| 1 | align=left | align=left | | 50.42 | Q | ||
| 2 | align=left | align=left | | 50.62 | Q | ||
| 3 | align=left | align=left | | 51.25 | Q | ||
| 4 | align=left | align=left | 51.63 | Q | |||
| 5 | align=left | align=left | | 51.84 | |||
| 6 | align=left | align=left |  | 51.85 | |||
| 7 | align=left | align=left | 52.57 | ||||
| 8 | align=left | align=left |  | 53.15 |
| Rank | Name | Nationality | Time | Notes | |||
|---|---|---|---|---|---|---|---|
| 1 | align=left | align=left | | 51.27 | Q | ||
| 2 | align=left | align=left | 52.08 | Q | |||
| 3 | align=left | align=left | 52.08 | Q | |||
| 4 | align=left | align=left | | 52.25 | Q | ||
| 5 | align=left | align=left | 52.51 | ||||
| 6 | align=left | align=left | | 52.77 | |||
| 7 | align=left | align=left | | 53.63 | |||
| 8 | align=left | align=left |  | 54.42 |
16 September
| Rank | Name | Nationality | Time | Notes | |||
|---|---|---|---|---|---|---|---|
| 1 | align=left | align=left | 51.82 | Q | |||
| 2 | align=left | align=left | | 52.15 | Q | ||
| 3 | align=left | align=left | | 52.30 | q | ||
| 4 | align=left | align=left | | 52.88 | q | ||
| 5 | align=left | align=left | 53.77 | ||||
| 6 | align=left | align=left |  | 57.50 |
| Rank | Name | Nationality | Time | Notes | |||
|---|---|---|---|---|---|---|---|
| 1 | align=left | align=left | | 52.10 | Q | ||
| 2 | align=left | align=left | | 52.77 | Q | ||
| 3 | align=left | align=left |  | 52.97 | |||
| 4 | align=left | align=left |  | 53.25 | |||
| 5 | align=left | align=left | 55.09 | ||||
| align=left | align=left |  | DNF |
| Rank | Name | Nationality | Time | Notes | |||
|---|---|---|---|---|---|---|---|
| 1 | align=left | align=left | | 51.39 | Q | ||
| 2 | align=left | align=left | | 52.17 | Q | ||
| 3 | align=left | align=left | 52.45 | q | |||
| 4 | align=left | align=left | 53.05 | ||||
| 5 | align=left | align=left |  | 53.33 | |||
| 6 | align=left | align=left | 55.93 | ||||
| 7 | align=left | align=left | | 56.39 |
| Rank | Name | Nationality | Time | Notes | |||
|---|---|---|---|---|---|---|---|
| 1 | align=left | align=left | | 51.75 | Q | ||
| 2 | align=left | align=left | 51.77 | Q | |||
| 3 | align=left | align=left | | 52.03 | q | ||
| 4 | align=left | align=left | 52.23 | q | |||
| 5 | align=left | align=left | | 52.50 | q | ||
| 6 | align=left | align=left | | 53.32 | |||
| 7 | align=left | align=left | | 54.10 |
| Rank | Name | Nationality | Time | Notes | |||
|---|---|---|---|---|---|---|---|
| 1 | align=left | align=left | 52.56 | Q | |||
| 2 | align=left | align=left | | 52.73 | Q | ||
| 3 | align=left | align=left |  | 53.00 | |||
| 4 | align=left | align=left | 53.17 | ||||
| 5 | align=left | align=left | 53.19 | ||||
| 6 | align=left | align=left | | 53.30 |
According to an unofficial count, 32 athletes from 24 countries participated in the event.