The medicinal benefits of Allium vegetables,especially garlic,have been notedthroughout recorded history.The known health benefits of Allium vegetablesand their constituents include cardiovascular protective effects,stimulation ofimmune function,reduction of blood glucose level,radioprotection,improvementof memory loss,protection against microbial,viral and fungal infections,as well asanticancer effects.Population-based case control studies have suggested aninverse correlation between dietary intake of Allium vegetables and the risk ofdifferent types of cancers.The anticarcinogenic effect of Allium vegetables in-cluding garlic is attributed to organosulfur compounds (OSC),which are highlyeffective in affording protection against cancer in animal models induced by avariety of chemical carcinogens.More recent studies have shown that certainnaturally occurring OSC analogues can suppress proliferation of cancer cells inculture and in vivo.The OSC-induced changes in the proliferation of cancer cellsare frequently associated with perturbations in cell cycle progression and induc-tion of G2/M phase arrest.The OSC have also been demonstrated to induceapoptosis via the intrinsic pathway by altering the ratio of the Bcl-2 family ofproteins both in cell culture and in in vivo models.Anti-angiogenic activity forgarlic-derived OSC has also been documented.This article summarizes currentknowledge on molecular targets of cancer chemoprevention by OSC.