The antioxidant and antimicrobial protection of diallyl sulfide (DAS), diallyl disulfide (DADS), s-ethyl cysteine (SEC), n-acetyl cysteine (NAC) in ground beef against discoloration, lipid oxidation and microbial contamination were studied. The exogenous addition of these garlic-derived organosulfur compounds significantly delayed both oxymyoglobin and lipid oxidations (P<0.05). The antioxidant protection from these organosulfur compounds was dose-dependent (P<0.05), and showed significantly greater antioxidant activity than α-tocopherol (P<0.05). The presence of DAS and DADS in ground beef significantly reduced total aerobes and inhibited the growth of five inoculated pathogenic bacteria, Salmonella typhimurium, Escherichia coli O157:H7, Listeria monocytogenes, Staphyllococcus aureus and Campylobacter jejuni (P<0.05). These results suggested the application of these organosulfur compounds in meat or other food systems could enhance color, lipid and microbial safety.