To evaluate the effect of injections of gamma-globulin upon the course of asthma, observations were made with 22 asthmatic children ranging in age from 1½ to 5½ years. They had suffered from asthma from 1 to 13 years and were selected as subjects because they had not made satisfactory improvement under allergic management over an average of 2.4 years. They were placed in two groups by random assignment, one of which received injections of gamma-globulin. Without knowledge of the treatment being given, one author examined each child at the time of each injection and one month after the last injection. Roentgenograms, vital capacity, complete blood counts and chemical determination of the blood proteins were performed at the initial and final visits. Fifteen of the twenty-two patients improved clinically, eight in the treatment group and seven in the control group. No significant differences between the groups were noted in the amount of asthma, physical growth, hemoglobin value or eosinophilia. The concentration of gamma-globulin in the serum increased in the treated patients. Nevertheless, there was no difference in the incidence of infection in the two groups and in both it was equal to that in a normal population. This double-blind controlled study offers no evidence to support the view that treatment with gamma-globulin has a beneficial effect on the course of chronic asthma in children.