The 1991 PBA All-Filipino Conference Finals was the best-of-5 basketball championship series of the 1991 PBA All-Filipino Conference, and the conclusion of the conference's playoffs. The Purefoods Tender Juicy Hotdogs and Diet Sarsi Sizzlers played for the 49th championship contested by the league. Purefoods Tender Juicy Hotdogs wins their first-ever All-Filipino crown and their second PBA title, in a hard-fought, thrilling series over second-year ballclub Diet Sarsi Sizzlers, 3 games to 2.