| Singles | |
|---|---|
| 2004 Mercedes Cup | |
| Champion |
|
| Runner-up |
|
| Final score | 5–7, 6–2, 6–0, 1–6, 6–3 |
Guillermo Coria was the defending champion, but did not participate.
Guillermo Cañas won the title, defeating Gastón Gaudio 5–7, 6–2, 6–0, 1–6, 6–3 in the final.
All seeds receive a bye into the second round.