Here we studied the possible cytotoxic and apoptotic effects of Anatolian endemic mountain viper,Montivipera bulgardaghica albizona(M.b. albizona) venom on human PC-3 and DU-145 prostate cancer cell lines.M.b. albizonavenom induced cytotoxicity and apoptosis of both prostate cancer cells in a concentration-dependent manner. Protein array results revealed that the levels of major components of the mitochondrion-initiated and the extrinsic death receptor-mediated pathways were significantly changed in prostate cancer cells by venom treatment. These data suggest that one or more of the purified components of theM.b. albizonavenom may serve as an appropriate therapeutic agent for prostate cancer. Further bioactivity guided studies are required for the identification of bioactive compounds ofM.b. albizonavenom.