Sulforaphane (SFN) is an organosulfur product of found isothiocyanates in vegetables. The chemopreventive effects of SFN have revealed that there is a link between excessive consumption of SFN-rich vegetables and cancer formation without possible toxicological consequences. We aimed to evaluate the cellular outcome of SFN from a toxicological perspective, particularly for renal cells including clear cell adenocarcinoma (769-P) and human embryonic renal epithelial (293T) cells. The viability/cytotoxicity experiments were performed with methyl thiazole diphenyl tetrazolium (MTT) and lactate dehydrogenase (LDH) assays. IC₅₀-dependent, non-cytotoxic concentrations were used for the determination of cell cycle status and apoptosis by using flow cytometry and western blot. A certain concentration of SFN effectively altered apoptotic/necrotic behavior in 769-P compared to the control group 293T. Cell cycle status remained stable while showing a decreased proliferation profile for 769-P cells. The percentage of the S phase from the cell cycle in 293T cells significantly reduced without affecting proliferation status. The use of SFN as an alternative to traditional treatments might be considered for the battle against renal cell carcinoma but the current findings showed that caution should be applied particularly for renal cells. Our study will provide a basis for future in vivo studies to support traditional cancer therapies.