Unión was founded in 1948 as a football club, but it expanded into several different sports, including basketball, where the team currently plays at Torneo Nacional de Ascenso (TNA), the second division of Argentine basketball league system.

Other sports practised at the club are gymnastics, roller skating, rugby union, martial arts, tennis and volleyball.

The club won its first official title, the Asociación Rafaelina de Básquetbol championship, in 1987 being coached by Roberto Vico.

The club spent two seasons in the Nacional B until the team had to leave the tournament due to financial problems.

[citation needed] In 2009, Unión promoted to Liga Nacional de Básquetbol, the top division of Argentine basketball.