The men's 4 x 400 metres relay event at the 2003 European Athletics U23 Championships was held in Bydgoszcz, Poland, at Zawisza Stadion on 20 July.
| Gold | Rafał Wieruszewski Kacper Skalski Daniel Dąbrowski Marek Plawgo  | |
| Silver | Sebastian Gatzka Christian Duma Steffen Sattelmaier Bastian Swillims | |
| Bronze | Roman Matveyev Dmitriy Petrov Aleksandr Borshchenko Amdrey Polukeyev  |
20 July
| Rank | Nation | Competitors | Time | Notes | ||
|---|---|---|---|---|---|---|
| align=left | | 3:03.32 | ||||
| align=left | 3:03.36 | |||||
| align=left | | 3:04.18 | ||||
| 4 | align=left | 3:06.61 | ||||
| 5 | align=left |  | 3:06.79 | |||
| 6 | align=left | 3:06.79 | ||||
| 7 | align=left |  | 3:08.98 | |||
| align=left |  | DNF |
According to an unofficial count, 32 athletes from 8 countries participated in the event.
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