Fourteen teams participated in the 1989–90 Cypriot First Division.
The team with the most points at the end of the season crowned champions.
The last two teams were relegated to the 1990–91 Cypriot Second Division.
EPA Larnaca, Keravnos and Omonia Aradippou were relegated from previous season and played in the 1989–90 Cypriot Second Division.
They were replaced by the first two teams of the 1988–89 Cypriot Second Division, Evagoras and Akli.