Tetrandrine is a bisbenylisoquinoline alkaloid isolated from the dried root of Stephenia tetrandra S Moore. Tetrandrine exhibits very broad pharmacological actions, including anti-tumor activity. The beneficial effects of tetrandrine on tumor cell cytotoxicity and radiosensitization, multidrug resistance, normal tissue radioprotection, and angiogenesis are most promising and deserve great attention. Tetrandrine has the potential either as a tumoricidal agent or as an adjunct to chemotherapy and radiotherapy.