In recent years, the incidence of breast cancer and the associated mortality have increased throughout the world. In general, chemotherapy, surgery, and radiotherapy are the common methods of cancer treatment. It should be mentioned that chemical drugs, other than cancer cells, also effect on healthy cells, their beneficial factors (i.e., enzymes and substrates related to DNA replication. For this reason, researchers have so far attempted to identify new natural/synthetic compounds with anti-cancer characteristics. In the present survey, the effect of the extract of Capparis spinosa on the breast cancer cell line MCF-7 was evaluated. In order to select an appropriate dose and determine the cytotoxicity of theC. spinosa compound, the MTT test was employed. On the other hand, for the evaluation of the effect of this compound on the protein expression and the mRNA of Bcl-2 and Bax, western blotting and real-time PCR were applied, respectively. The evaluation of C. spinosa cytotoxicity showed that this compound has IC50, equivalent to 70 milligram/milliliter. In addition, it was stated that while the expression rate of protein and the mRNA of the Bax gene was significantly increased, the expression rate of protein and the mRNA of Bcl2 gene was not altered. In general, the results obtained from this survey demonstrated the effectiveness of this herbal complement against breast cancer. With regard to the naturalness of this product as well as the low cost and the easy availability, using this compound in the dietary regimencan assist in the treatment of breast cancer.