1990 Athens Open – Singles

Ronald Agénor was the defending champion, but did not participate this year.

Mark Koevermans won the tournament, beating Franco Davín in the final, 5–7, 6–4, 6–1.

Seeds

 * 1) 🇦🇹 Thomas Muster (second round)
 * 2) 🇪🇸 Emilio Sánchez (first round)
 * 3) 🇦🇷 Guillermo Pérez Roldán (quarterfinals)
 * 4) 🇪🇸 Jordi Arrese (semifinals)
 * 5) 🇦🇷 Franco Davín (final)
 * 6) 🇪🇸 Javier Sánchez (quarterfinals)
 * 7)  Mark Koevermans (champion)
 * 8) 🇦🇷 Horacio de la Peña (second round)