1989–90 Cuban National Series
| 1989–90 Cuban National Series Serie Nacional de Béisbol 1989–90 | |
|---|---|
| League | Cuban National Series |
| Sport | Baseball |
| Games | 48 |
| Teams | 18 |
| Eastern zone | |
| Best record | Santiago de Cuba (36–12) |
| Western zone | |
| Best record | Henequeneros (37–11) |
| Postseason | |
| Finals champions | Henequeneros |
| Runners-up | Santiago de Cuba |
In the 29th season of the Cuban National Series, the postseason format was changed. The league directly matched its two division winners in a best-of-seven series for the league championship, while the two division runners-up played a best-of-five series for third place. A four-team round-robin tournament had previously been used, since the 1985–86 season. The 18 teams of the league, and the regular-season schedule of 48 games, remained unchanged.
Henequeneros of Matanzas Province defeated Santiago de Cuba, four games to two, for the championship. Third place was won by Industriales over Granma.