Abstract Procedures for the isolation, purification, and crystallization of wheat germ agglutinin are described. The agglutinin was purified 184-fold to homogeneity from commercial wheat germ lipase. A molecular weight of 23,500 was estimated for the protein by means of sedimentation equilibrium and sodium dodecyl sulfate gel electrophoresis. The agglutinin is a glycoprotein. Amino acid and carbohydrate compositions are reported. The protein contains unusually high half-cystine and glycine. Glucose was found to be the major carbohydrate constituent.