The Baloncesto Superior Nacional or BSN (lit. "National Superior Basketball") is the main Puerto Rican men's basketball league. It currently has 8 teams, but has had many teams in several cities of the island. The league was established in 1929. It has produced players that have distinguished themselves in the NBA, European Leagues, and other leagues. Also most of the players in the Puerto Rico men's national basketball team are playing in the league.

For the 2012 season, which began the 1st of March, each team will play 30 games in a single table format. The regular season is followed by a Round Robin with the best 6 teams. The season concludes with the finals, here two teams compete in the best of seven games.

The Vaqueros de Bayamón and the Atléticos de San Germán are the current leaders in all time championships with fourteen. The Leones de Ponce have twelve.

The league began in 1930, and is noted for having had several head coaches who went on to achieve international recognition later in their careers. Among these are Basketball Hall of Fame members Tex Winter, who coached the Ponce Lions in the early 1950s, Red Holzman, who also coached Ponce in the 1960s, and Phil Jackson, who coached Quebradillas and Isabela in the late 1980s. Others include Lou Rossini, Del Harris, P.J. Carlessimo, Bernie Bickerstaff and Herb Brown.