and Summary This paper is concerned with the nutritional properties of the soybean and of various food products derived from it. Although primary consideration is given to the protein, cognizance is made of other nutrients such as vitamins and minerals. Much of our knowledge concerning the nutritional properties of the soybean has been derived from experiments with animals, and such knowledge is frequently directly applicable to human nutrition. Nutritional experiments with human subjects pose special problems, the most difficult of which is acceptability. People will not eat a certain food simply “because it is good for them.” Thus, the most serious hurdle to be overcome in the development of products containing soybean proteins is frequently not a nutritional one but one of consumer acceptance.