The 1988–89 Primera División season was the second category of the Spanish basketball league system during the 1988–89 season. It was the first played with the name of Primera División.
Format
16 teams played this season.
Regular Season
League of 16 teams in a single group where they play all against all in two rounds.
The last two teams are relegated to Segunda Division.
Promotion playoffs
The top 8 play two knockout rounds for promotion. The first round is the best of 3 matches (first and third matches are played at the home of the best classified in the previous phase) and the second to the best of 5 (first, third and fifth matches are played at the home of the best classified in the phase previous). The two winners go up to the ACB League.
Relegation playoffs
Those classified between the 11th to 14th places play a best of 5 matches (first, third and fifth matches are played at the home of the best classified in the previous phase), the 2 losers go down to Segunda Division.
Teams
Promotion and relegation (pre-season)
A total of 16 teams contested the league, including 11 sides from the 1987–88 season, two promoted from the Segunda División and three Wild Cards.
Teams promoted from Segunda División
Cajahuelva
CB Torrejon
Wild Cards
CAB Obradoiro, who obtained a relegation place the previous season.
Tenerife Sur, who obtained a relegation place the previous season.
Syrius Patronato
Teams that resigned to participate
Ordenadores APD Mataró
CB Tizona sold his place to Caja Badajoz, who obtained a relegation place the previous season.