Forty patients with active systemic lupus erythematosus were treated with methylprednisolone. Their ages ranged from 11 to 73 years. The pattern of clinical improvement was similar to that previously seen after the use of prednisone, triamcinolone, and other anti-inflammatory hormones; the fever abated in 24 hours, joint pains disappeared in several days, and pleural effusion and cutaneous lesions subsided in one to several weeks. The doses needed were of the same order of magnitude as those of prednisone and triamcinolone; the mean initial dose was 29.2 and the mean maintenance dose 25.9 mg. per day. While methylprednisolone seemed to differ from the other steroids with respect to some side-effects, the incidence of moonface, hirsutism, acne, and striae was about the same.