Pharmacological and preventive properties of Vitex trifolia leaf extracts are well known, but the anticancer activity of methanol and petroleum ether extracts of Vitex trifolia leafs on human breast cancer cells have not been explored so far. Therefore, the present study was designed to investigate the cytotoxic activities of these extracts against MCF-7 and Vero cell line. Cells were exposed to 125 to 500 μg/ml of extracts of Vitex trifolia for 72 h. Post-treatment, percent cell viability was studied by 3-(4, 5-dimethylthiazol-2yl)-2, 5-biphenyl tetrazolium bromide (MTT) assays. The results showed that petroleum ether and methanol extracts significantly reduced cell viability of MCF-7 cells in a concentration dependent manner. Concentrations of 125 μg/ml and above of petroleum ether and 500 μg/ml of methanol extract were found to be cytotoxic in MCF-7 cells. Cell mortality at 125, 250 and 500 μg/ml of petroleum ether extract was recorded as 98.80%, 93.40% and 87.75% respectively, whereas the concenrations 125, 250 and 500 (μg/ml ) of methanol extract detected values were 79.98%, 75.70% and 70.25%, respectively by MTT assay. MCF-7 and Vero cells exposed to 125, 250 and 500 μg/ml. The data revealed that the treatment with petroleum ether and methanol of Vitex trifolia leaf extract induced cell death in MCF-7 cells. Meanwhile the same extract showed a moderate inhibition against Vero cell lines. It may be concluded that Vitex trifolia can cause cell death in MCF-7 cancer cells which can be considered as a promising chemotherapeutic agent in breast cancer treatment.