We have previously reported that tetrandrine reduced hepatic stellate cell activation and collagen accumulation in liver ﬁbrosis induced by biliary obstruction. In the present study, we examined the apoptosis-inducing effect of tetrandrine on activated hepatic stellate cells, as the therapeutic goal in hepatic ﬁbrosis is to eliminate the activated hepatic stellate cells by apoptosis. We used rat hepatic stellate cells transformed by Simian virus 40 (T-HSC/Cl-6) to overcome the limitations inherent in studying primary cultures of hepatic stellate cells. Tetrandrine treatment at doses of 25 and 50 µg/ml for 12 h induced apoptosis as conﬁrmed by DNA fragmentation and increased sub-G1 DNA content as detected by ﬂow cytometric analysis. Tetrandrine also induced the activation of caspase-3 protease and subsequent proteolytic cleavage of poly(ADP-ribose) polymerase. In conclusion, our results demonstrate that tetrandrine induces apoptosis of T-HSC/Cl-6 cells, and these results should contribute to the development of new agents for the treatment of hepatic ﬁbrosis. Copyright © 2004 John Wiley & Sons, Ltd.