Summary The results of cortisome and ACTH therapy in 122 closely followed cases of active rheumatic fever with carditis have been presented. The number of deaths occurring among all rheumatic fever admissions during the period of availability of hormone for therapy has been less than among a similar earlier group. The incidence of reversal of signs of valvular lesions in first attacks of hormone-treated patients has been greater than that of the prehormone period. Our criteria for the selection of cases for cortisone or ACTH therapy, the dosage, duration of treatment, and the precautions taken have been stated. We administer these substances only to closely supervised hospitalized patients in whom we can demonstrate active carditis.