Abstract : In this study we demonstrated that vitamin E isoforms, tocopherols and tocotrienols, have variable growth inhibitory effects on both types of prostate cancer cell line models. The gamma isoforms are more effective than the alpha isoforms and the tocotrienols are more effective than the tocopherols. This study further showed that the vitamin E-mediated inhibition of cell proliferation is preferential for cancer cells at concentrations of about 40 M or lower. Delta-tocotrienol (DT3), in particular, is infective against normal prostate epithelial cells but highly effective against LNCaP cancer cells. Collectively, our data supports the view that tocotrienols, particularly DT3 may prove very useful as chemotherapeutic or chemopreventive agents for treating prostate cancer. Our next will be to initiate experiments in animal models and then to initiate clinical studies