2008–09 Lega Basket Serie A

Montepaschi Siena swept virtually all before them domestically, winning the SuperCoppa Italiana before the season and the Coppa Italia at midseason, losing in the league only once (at Fortitudo Bologna), and going unbeaten through the playoffs to claim their third straight title.

The Italian Supercup is played as a single match before the start of the season between the previous year's Serie A champion and Coppa Italia winner (if a club wins both, the match instead pits the top two teams from the previous season's league).

At end of regular season: Following the season, the owner of Fortitudo (GMAC) Bologna failed to make required payments to remain in the Italian professional ranks, and the club were further relegated to the country's third level, the nominally amateur Serie A Dilettanti.

[1] The top eight teams at the halfway point of the regular season (15 rounds) competed in the Italian Cup, seeded according to their league placement at that time.

The playoffs, which began on May 18, featured the top eight teams from regular-season play, seeded by league position.