2004 ATP Buenos Aires – Singles

Carlos Moyá was the defending champion but lost in the final 6–4, 6–1 against Guillermo Coria.

Seeds

 * 1) 🇦🇷 Guillermo Coria (champion)
 * 2) 🇪🇸 Carlos Moyá (final)
 * 3)  Nicolás Massú (quarterfinals)
 * 4) 🇧🇷 Gustavo Kuerten (first round)
 * 5) 🇦🇷 Agustín Calleri (second round)
 * 6) 🇦🇷 Mariano Zabaleta (quarterfinals)
 * 7) 🇦🇷 Gastón Gaudio (first round)
 * 8) 🇦🇷 Juan Ignacio Chela (second round)