| Host city | |
|---|---|
| Nations | 168 |
| Athletes | 1261 |
| Events | 44 |
| Dates | 12–18 July |
| Main venue | Stadio Olimpico Carlo Zecchini |
The 2004 World Junior Championships in Athletics were held in Grosseto, Italy on 12–18 July.



* Host nation (Italy)
| Rank | Nation | Gold | Silver | Bronze | Total |
|---|---|---|---|---|---|
| 1 | 13 | 3 | 3 | 19 | |
| 2 | 7 | 8 | 3 | 18 | |
| 3 | 4 | 2 | 1 | 7 | |
| 4 | 3 | 0 | 1 | 4 | |
| 5 | 2 | 4 | 6 | 12 | |
| 6 | 2 | 4 | 0 | 6 | |
| 7 | 2 | 0 | 1 | 3 | |
| 2 | 0 | 1 | 3 | ||
| 9 | 1 | 4 | 3 | 8 | |
| 10 | 1 | 1 | 1 | 3 | |
| 1 | 1 | 1 | 3 | ||
| 12 | 1 | 1 | 0 | 2 | |
| 13 | 1 | 0 | 2 | 3 | |
| 14 | 1 | 0 | 0 | 1 | |
| 1 | 0 | 0 | 1 | ||
| 1 | 0 | 0 | 1 | ||
| 1 | 0 | 0 | 1 | ||
| 18 | 0 | 4 | 5 | 9 | |
| 19 | 0 | 2 | 1 | 3 | |
| 20 | 0 | 1 | 0 | 1 | |
| 0 | 1 | 0 | 1 | ||
| 0 | 1 | 0 | 1 | ||
| 0 | 1 | 0 | 1 | ||
| 0 | 1 | 0 | 1 | ||
| 0 | 1 | 0 | 1 | ||
| 0 | 1 | 0 | 1 | ||
| 0 | 1 | 0 | 1 | ||
| 0 | 1 | 0 | 1 | ||
| 0 | 1 | 0 | 1 | ||
| 30 | 0 | 0 | 4 | 4 | |
| 31 | 0 | 0 | 3 | 3 | |
| 32 | 0 | 0 | 1 | 1 | |
| 0 | 0 | 1 | 1 | ||
| 0 | 0 | 1 | 1 | ||
| 0 | 0 | 1 | 1 | ||
| 0 | 0 | 1 | 1 | ||
| 0 | 0 | 1 | 1 | ||
| 0 | 0 | 1 | 1 | ||
| 0 | 0 | 1 | 1 | ||
| Totals (39 entries) | 44 | 44 | 44 | 132 | |
According to an unofficial count through an unofficial result list, 1261 athletes from 168 countries participated in the event. This is in agreement with the official numbers as published.