2003 International Raiffeisen Grand Prix – Singles

Nicolás Lapentti was the defending champion but did not compete that year.

Andy Roddick won in the final 6–3, 6–2 against Nikolay Davydenko.

Seeds
A champion seed is indicated in bold text while text in italics indicates the round in which that seed was eliminated.

• # 🇺🇸 Andy Roddick (champion)

• # 🇪🇸 Albert Costa (second round)

• # 🇦🇷 Guillermo Coria (withdrew because of a groin muscle injury)

• # 🇺🇸 Taylor Dent (first round)

• # 🇺🇸 Jan-Michael Gambill (first round)

• # 🇷🇺 Nikolay Davydenko (final)

• # 🇸🇰 Karol Kučera (first round)

• # 🇪🇸 David Sánchez (semifinals, retired because of a foot blister)