1990 Athens Open
Date	1–7 October
Edition	5th
Category	World Series
Draw	32S / 16D
Prize money	$125,000
Surface	Clay / outdoor
Location	Athens, Greece
Champions
Singles
Mark Koevermans[1]
Doubles
Sergio Casal / Javier Sánchez[2]
← 1989 · ATP Athens Open · 1991 →

The 1990 ATP Athens Open was a men's tennis tournament played on outdoor clay courts in Athens in Greece that was part of the World Series of the 1990 ATP Tour. It was held from 1 October through 7 October 1990. Seventh-seeded Mark Koevermans won the singles title.^[3]

Finals

Singles

Mark Koevermans defeated Franco Davín 5–7, 6–4, 6–1

• It was Koevermans' only singles title of his career.

Doubles

Sergio Casal / Javier Sánchez defeated Tom Kempers / Richard Krajicek 6–4, 6–3

• It was Casal's 7th title of the year and the 32nd of his career. It was Sánchez's 4th title of the year and the 10th of his career.