Nicolás Massú was the defending champion but lost in the first round to Agustín Calleri.
Carlos Moyà won in the final 6–3, 4–6, 6–4 against Guillermo Coria.
Seeds
Carlos Moyá (champion) David Nalbandian (quarterfinals) Fernando González (second round) Gastón Gaudio (semifinals) Juan Ignacio Chela (quarterfinals) Gustavo Kuerten (semifinals) Nicolás Lapentti (second round) Guillermo Coria (final)
Draw
Finals
Top half
Bottom half
External links 2003 Copa AT&T Main Draw 2003 Copa AT&T Qualifying Draw