Garlic has long been used medicinally for many diseases, including cancer. One of the active garlic components is diallyl sulfide (DAS), which prevents carcinogenesis and reduces the incidence rate of several cancers. In this study, non-cancerous MCF-10A cells were used as a model to investigate the effect of DAS on Benzo (a)pyrene (BaP)-induced cellular carcinogenesis. The cells were evaluated based on changes in proliferation, cell cycle arrest, the formation of peroxides, 8-hydroxy-2-deoxyguanosine (8-OHdG) levels, the generation of DNA strand breaks, and DNA Polymerase β (Pol β) expression. The results obtained indicate that when co-treated with BaP, DAS inhibited BaP-induced cell proliferation (p 2O2 in the extracellular medium and an increase in 8-OHdG levels of treated cells. All DAS concentrations inhibited BaP-induced DNA strand breaks through co-treatment and pre-treatment methods at all time points evaluated. Co-Treatment with 60 μM DAS increased DNA Pol β expression in response to BaP-induced lipid peroxidation and oxidative DNA damage. These results indicate that DAS effectively inhibited BaP-induced cell proliferation, cell cycle transitions, ROS, and DNA damage in an MCF-10A cell line. These results provide more experimental evidence for garlic’s antitumor abilities and corroborate many epidemiological studies regarding the association between the increased intake of garlic and the reduced risk of several types of cancer.