1977–78 Cuban National Series

The 17th season of the Cuban National Series saw Vegueros of Pinar del Río Province win the title, finishing with a slim lead over Industriales of Havana. The makeup of the league was directly influenced by the administrative restructuring of the provinces of Cuba. The league expanded from 14 to 18 teams, and the regular season increased from 39 to 51 games (although some teams played as few as 46 games).

Restructuring
Many teams were reconstituted to align with Cuba's restructuring into 14 provinces and one special municipality, announced in December 1976.

The league expanded to 18 teams: 11 provinces fielded a single team each, three provinces fielded two teams each, and the special administrative area of Isla de Pinos (later renamed Isla de la Juventud) fielded a team.

The three provinces fielding two teams each were:
 * Ciudad de La Habana Province (the city of Havana): Industriales and Metropolitanos
 * Pinar del Río Province: Vegueros and Forestales
 * Matanzas Province: Citricultores and Henequeneros

The 1977–78 season was also the first in which aluminum bats were used league-wide replacing the wooden bats, and was also the first in which the designated hitter was used, replacing the pitcher's turn at bat, following an off-season decision by the Baseball Federation of Cuba and by the National Sports Institution, following the lead of the American League of Major League Baseball four years before.

Standings
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