Seventeen unselected patients with relapsed or refractory multiple myeloma were treated with oral prednisolone 60 mg per m2 for five consecutive days with nine-day treatment-free intervals. Of the fourteen patients who completed at least six courses of treatment there were five good responses (Chronic Leukemia-Myeloma Task Force Criteria), five partial responses and four failures. Median survival (all seventeen patients) was between 19 and 20 months. Eight patients achieved plateau phase (median duration 9 months). Eleven patients showed improved performance status and four became free of transfusion support. The commonest side-effect was bacterial pulmonary infection. Peptic ulceration occurred in two patients despite prophylactic ranitidine. Other steroid-related side-effects were mild and well tolerated. This study provides further evidence for the efficacy of higher dose steroid regimens in relapsed or refractory myelomatosis and confirms that durable remissions may be achieved. Responders show a gratifying improvement in quality of life and are spared the many toxicities of combination cytotoxic chemotherapy. Further studies of high dose steroid regimens in first-line therapy, especially in patients with bone marrow suppression, are clearly merited.