The institution of a milk-free diet is sometimes considered desirable for infants who exhibit an allergic response to milk protein. The use of soy bean flour in these diets has been advocated. The advantages of soy beans in infant feeding have been discussed by Tso 1 and by Hill and Stuart.2 Soy bean flour is rich in protein, but the protein is of poorer quality than milk protein, and consequently must be fed at a higher level, from 20 to 22 per cent of the total calories.3 The mineral content of soy bean flour differs considerably from that of milk.2 Soy beans are rich in potassium and magnesium, but contain very little sodium, calcium and chloride. The percentage of phosphorus is not very different from the percentage of phosphorus in milk solids. In feeding soy bean preparations to infants, it is customary to add sodium chloride and a source of calcium, usually the carbonate or lactate. The phosphorus content has been considered adequate.4 The caloric value of the soy bean flour is increased by the addition of oil and sugar. Cod liver oil and a source of vitamin C also must be given.