The 1989 PBA Open Conference Finals was the best-of-7 series basketball championship of the 1989 PBA Open Conference, and the conclusion of the conference's playoffs. The San Miguel Beermen and Formula Shell Zoom Masters played for the 42nd championship contested by the league. The finals series serves as a rematch between these two teams that battled in the Third Conference finals last season. The San Miguel Beermen repeated against the Formula Shell Zoom Masters in a similar 4–1 conquest and retains the PBA Open Conference crown.