Eleven derivatives from Antrodia camphorata were isolated in order to evaluate their selective cytotoxicity toward 14 types of human cancer cell and two non-transformed cell types. Among these triterpenoids, methyl antcinate A (MAA) exhibited the most potent spectrum of anticancer effects in KB cells, four different oral cancer cell lines (TSCCa, GNM, OC-2, and OEC-M1), Panc-1, BT474, PC-3, OVCAR-3, HeLa, and U2OS cells with high selectivity indices (CC(50)/IC(50)). The expression of B-cell lymphoma 2 (Bcl-2), Bcl-2-associated X protein (Bax), and poly(ADP-ribose) polymerase (PARP) of PC-3 cells tested by western blotting suggested that MAA exerts cell death through the caspase-dependent cascade and the Bax-mediated mitochondrial apoptotic pathway, not only on liver and oral cancer cells but on other types as well, including prostate cancer, in a dose-dependent manner. In addition to MAA, methyl antcinate B, dehydroeburicoic acid, and 15α-acetyl-dehydrosulfurenic acid also exhibited significant selective cytotoxic effects to respective cancer cells. Modifications of these triterpenoids may lead to the development of more potent anticancer drugs.