Three patients with alopecia areata were evaluated for abnormalities in their corticosteroid metabolism. Determinations were made of plasma and urinary 17-hydroxycorticosteroid and urinary 17-ketogenic steroids before and after corticotropin stimulation. Radioactive cortisol and its metabolites were determined at various intervals after intravenous infusion of cortisol and the pattern of their disappearance established. No consistent abnormalities were noted in the patients studied.