Symptomatic relapses of autoimmune chronic active hepatitis during steroid withdrawal are well known. However, the exquisite sensitivity of some patients to very small decrements in steroid dose has not been emphasized. Reported here are two patients who developed, during steroid withdrawal, eight relapses of their disease; symptomatic and biochemical relapses occurred within 3 weeks after prednisone had been reduced from 2.5 mg every other day to 1.75 mg every other day in one patient and from 2.5 mg per day to zero in the other. "Physiologic" doses of prednisone may be therapeutic in some patients with autoimmune chronic active hepatitis.