Background: Cervical and breast cancer are considered to be the most common cause of death among Iranian women. Various studies have shown that probiotics are effective fighting cancer. The aim of the present study was to investigate the effect of Lactobacillus brevis on apoptosis and casp (casp3, casp8) gene expression in HeLa cancer cells. Materials & Methods: In this study, L. brevis bacteria were collected from the vaginal fluid of females referred to Alzahra Hospital and isolated and cultured in MRS agar medium. Inhibition of HeLa cancer cell proliferation by bacteria was evaluated by MTT assay. Apoptosis of cancer cells was measured by fluorescent microscopy using DAPI method. Finally, expression of Caspase and akt genes was measured by Real time PCR. Results: The results indicated that L. brevis had the same effect on HeLa cancer cells (P=0.42, P=0.26). On the other hand, there was no significant increase in akt gene expression (p> 0.05). Conclusion: Lactobacillus brevis bacteria can be considered biologically safe for the development of a novel, high-impact, low-throughput therapeutic strategy. On the other hand, side-by-side treatment and prevention against cancer will be costeffective.