Cancer is a major health problem which is considered as one of the most reasons of death worldwide. Breast cancer is a second cause of women death and estimated to have 2.1 million new cases. Traditional treatment of cancer based on different clinical approaches is included surgery, chemotherapy, radio therapy, hormone therapy and combination therapy which affect both cancer and normal cells. The present study investigated the anticancer potential of Cerastes vipera venom in comparison with Cisplatin drug on MDA-MB-231 breast cancer cell line. Cytotoxicity activity of tested material was evaluated using MTT assay. Cell cycle arrest was performed using propidium iodine DNA staining. Apoptotic detection was determined using annexin V-FTIC and for the detection of the genes Caspase 3, Caspase 8 & Caspase 9 were
determined by ELISA. The C. vipera venom, Cisplatin and PLA2 had IC50 as 3.4, 10.3, 35.1 μg/mL with MDA-MB-231 cell line respectively. Cell cycle has arrest of cells in G2/M of C. vipera venom and PLA2. Tested venoms have apoptotic effect against MDA-MB-231 cell line through elevation of Caspase 3, Caspase 8 & Caspase 9 genes.