The recovery of adrenocortical function during long-term corticosteroid treatment in a group of patients with asthmatic bronchitis was compared with that in a group of patients with sarcoidosis. At corresponding dosages of prednisone basal adrenocortical function as well as adrenocortical response to tetracosactrin stimulation was higher in the asthma patients than in those with sarcoidosis.The rate of recovery of adrenocortical function seems mainly to be determined by the dosage of corticosteroids during the initial stages of treatment rather than by the nature of the disease.