The use of lysozyme as a food preservative and the factors affecting lysozyme activity (temperature, chemicals, processing and complexes) is reviewed. Lysozyme inhibits the growth of deleterious organisms thus prolonging shelf life. Chemicals used to improve the preservative effect of lysozyme and those that inhibit the enzyme are discussed along with the stability of lysozyme in various chemical environments. Lysozyme has been used to preserve fresh fruits and vegetables, tofu bean curd, seafoods, meats and sausages, potato salad, cooked burdock with soy sauce, and varieties of semi-hard cheeses such as Edam, Gouda and some Italian cheeses. Lysozyme added to infant feeding formulae makes them more closely resemble human milk.