The 2008-2009 Season of BAI Basket (31st edition) ran from November 20, 2008 through May 16, 2009, with 12 teams playing in three different stages: in stage one (regular season) teams played a double round robin system. In stage two, the six best teams played a single round robin tournament in serie A and the last six did the same for the consolation group, serie B. Finally, in stage three (final four) the best four teams from serie A played in a round robin at four rounds for the title. The winners of the regular season and of the serie A are awarded a bonus point for the serie A and the final four, respectively.