1988–89 ACB season

The 1988–89 ACB season was the 6th season of the Liga ACB, after changing its name. The number of teams increased from 16 to 24. The format also changed. The 24 teams were divided into two groups of 12. After playing a league, 24 teams were divided into three groups of eight teams each. The first six of the white group and the champions of the red and blue groups played for the title.

FC Barcelona won their third ACB title, and their 6th overall. It was their third ACB title in a row.

Relegation Playoffs
Caja Guipúzcoa and Valvi Girona were relegated.

Qualification Games
(I-1) Clesa Ferrol vs. (II-3) Pamesa Valencia Clesa Ferrol win the series 3-0 and qualified to play in the A-1 the next season
 * Game 1 May 6, 1989 @ Ferrol: Clesa Ferrol 100 - Pamesa Valencia 76
 * Game 2 May 8, 1989 @ Ferrol: Clesa Ferrol 111 - Pamesa Valencia 107
 * Game 3 May 11, 1989 @ Valencia: Pamesa Valencia 79 - Clesa Ferrol - 83

(I-2) Magia de Huesca vs. (III-3) BBV Villalba BBV Villalba win the series 3-2 and qualified to play in the A-1 the next season
 * Game 1 May 6, 1989 @ Huesca: Magia de Huesca 67 - BBV Villalba 66
 * Game 2 May 8, 1989 @ Huesca: Magia de Huesca 66 - BBV Villalba 73
 * Game 3 May 11, 1989 @ Collado Villalba: BBV Villalba 82 - Magia de Huesca 53
 * Game 4 May 13, 1989 @ Collado Villalba: BBV Villalba 70 - Magia de Huesca 88
 * Game 5 May 16, 1989 @ Huesca: Magia de Huesca 67 - BBV Villaba 78

(III-1) Estudiantes Bose vs. (II-2) Mayoral Maristas Estudiantes Bose win the series 3-0 and qualified to play in the A-1 the next season
 * Game 1 May 6, 1989 @ Madrid: Estudiantes Bose 102 - Mayoral Maristas 80
 * Game 2 May 8, 1989 @ Madrid: Estudiantes Bose 87 - Mayoral Maristas 82
 * Game 3 May 11, 1989 @ Málaga: Mayoral Maristas 80 - Estudiantes Bose 91

(II-1) Cajabilbao vs. (III-2) Puleva Baloncesto Granada Cajabilbao win the series 3-2 and qualified to play in the A-1 the next season
 * Game 1 May 6, 1989 @ Bilbao: Cajabilbao 94 - Puleva Baloncesto Granada 87
 * Game 2 May 8, 1989 @ Bilbao: Cajabilbao 69 - Puleva Baloncesto Granada 79
 * Game 3 May 11, 1989 @ Granada: Puleva Baloncesto Granada 79 - Cajabilbao 83
 * Game 4 May 13, 1989 @ Granada: Puleva Baloncesto Granada 83 - Cajabilbao 79
 * Game 5 May 16, 1989 @ Bilbao: Cajabilbao 70 - Puleva Baloncesto Granada 69