1990–91 Cuban National Series
| 1990–91 Cuban National Series Serie Nacional de Béisbol 1990–91 | |
|---|---|
| League | Cuban National Series |
| Sport | Baseball |
| Games | 48 |
| Teams | 18 |
| Eastern zone | |
| Best record | Santiago de Cuba (33–15) |
| Western zone | |
| Best record | La Habana (34–13) |
| Postseason | |
| Finals champions | Henequeneros |
| Runners-up | Camagüey |
The 30th season of the Cuban National Series featured a postseason bracket tournament for the first time, with the top two teams from each division qualifying. Semifinals were played as best-of-three series, followed by a best-of-seven final series. Both semifinals were won by division runners-up, with Henequeros then defeating Camagüey to repeat as league champions. The 18 teams of the league were unchanged from recent seasons, as was each team's regular-season schedule of 48 games.