1989 Mercedes Cup – Singles

Andre Agassi was the defending champion, but did not compete this year.

Martín Jaite won the title by defeating Goran Prpić 6–3, 6–2 in the final.

Seeds
All seeds received a bye into the second round. • # Jakob Hlasek (second round)

• # 🇦🇷 Alberto Mancini (third round)

• # 🇺🇸 Aaron Krickstein (third round)

• # 🇺🇸 Kevin Curren (third round)

• # Miloslav Mečíř (second round)

• # 🇸🇪 Mikael Pernfors (third round)

• # 🇦🇷 Guillermo Pérez Roldán (quarterfinals)

• # 🇪🇸 Sergi Bruguera (semifinals)

• # 🇦🇺 John Fitzgerald (second round)

• # 🇪🇨 Andrés Gómez (second round)

• # Ronald Agénor (third round)

• # 🇪🇸 Jordi Arrese (quarterfinals)

• # 🇦🇺 Darren Cahill (second round)

• # 🇦🇷 Martín Jaite (champion)

• # Alexander Volkov (second round)

• # 🇸🇪 Jan Gunnarsson (third round)