Insoluble complex protein-lipid-calcium phosphate was formed on neutralization of dental enamel solution. Nonpolar lipids were extracted by chloroform-methanol mixture; the phospholipids maintained their connection with the solid phase. After incubation of the enamel precipitate with an anionic detergent the enamel protein became solubilized and was studied by means of electrophoresis. The role of proteins and lipids in calcification of the dental enamel is discussed. Biological calcification appears to operate via a universal mechanism, as evidenced by similarity in molecular structures of organic mixtures of various mineralized tissues.