Chemoprevention has been acknowledged as an important practical strategy for the management of cancer. Many naturally occurring substances present in the human diet have been identified as potential chemopreventive agents. Accordingly, in this study we have tested the effect of 13 plant-derived extracts which are in common use either as dietary supplements or traditional medicine for the growth-inhibitory effects on prostate cancer cell lines. First screening showed that Withania somnifera, Momordica charantia, Camellia sinensis (I & II), Curcuma longa and Polygonum cuspidatum are effective on highly metastatic PC-3M prostate cancer cell line. Second screening for selection of the most effective agent at narrow range lower concentrations showed that W. somnifera, C. longa and P. cuspidatum are most effective against different prostate cancer cell lines of varying metastatic potential and showed only a moderate effect on BG-9 normal skin fibroblasts. This observation suggests that these three agents have good potential for further studies against prostate cancer cell lines.