Concentrations of IgG, IgM, and IgA were determined in the sera of 11 children suffering from kwashiorkor and a variety of infections, and 11 well-fed children suffering from similar infections. There were no differences between the IgG and IgM values of the two groups, most of the results being high compared with those reported for normal children. The IgA values of the kwashiorkor cases were much higher than those of the controls and normal children.