This review contains a discussion of the physiological activity of the components of Allium vegetables. Organosulfur compounds in Allium vegetables, such as ajoene, diallyl sulfides and S allylcysteine, have cancer preventive activity in chemically induced animal cancer models. They also have inhibitory effects on proliferation of cancer cells in vitro. Allium vegetables have lipid and cholesterol lowering effect, and platelet aggregation inhibitory activity that help the prevention of cardiovascular diseases. Sulfur con taining compounds, especially allicin and ajoene, have antimicrobial activities against gram negative, positive bacteria and fungi. Moreover, Allium organosulfur compounds such as S allylcysteine showed reducing effects on the senescence related symptoms including cognition. Allium organosulfur compounds have significant importance in food industry as both biologically active ingredients and savory.