During the course of a study of plants of the family Araliaceae, antiproliferative activity was demonstrated by the crude saponin fraction of Trevesia palmata. After chromatographic purification, six new bisdesmosidic saponins (1-6), along with two known triterpenoid saponins, (7 and 8), were isolated. The structures of 1-6 were determined by (1)H-(1)H correlation spectroscopy (COSY-DQF, 1D TOCSY, 2D HOHAHA, 1D ROESY) and (1)H-(13)C (HSQC, HMBC) spectroscopy. The antiproliferative activity of compounds 1-8 and of their prosapogenins (2a-7a) prepared by alkaline hydrolysis, was evaluated using three continuous culture cell lines.