In recent studies, sulforaphane (SFN) has been seen to demonstrate antioxidant and anti-tumor activities as well as potent chemopreventive action against cancer. The present study investigates the anti-proliferation (using MTT assay, SFN demonstrated cytotoxic activity against GBM 8401 cell with IC(50) values at 35.52 μM) and induced apoptosis of SFN 24-h treatment in the cells of human brain malignant glioma GBM 8401 cells. We studied the MMP, caspase, MEK/ERK activation, and NF-κB transcription factor activity. Our results indicate that SFN inhibits cell proliferation as well as the activation of apoptosis in GBM 8401 cells. Both effects increased in proportion to the dosage of SFN, and apoptosis was induced via mitochondria- and caspase-dependent pathways. Daily s.c. injections of SFN for 3 weeks in severe combined immunodeficient mice (SCID) with GBM8401 s.c. tumors resulted in a decrease in mean tumor weight of 69-75 % compared with vehicle-treated controls. Our findings suggest that, in addition to the known effects on cancer prevention, SFN may provide antitumor activity in established malignant glioma.