Total lymphoid irradiation was administered to 32 patients with intractable rheumatoid arthritis. Twenty-four patients showed at least a 25% improvement in 3 of 4 disease activity parameters, which persisted during the followup period of up to 48 months. Eight of the 32 patients required adjunctive immunosuppressive drug therapy to maintain improvement. Four patients died after total lymphoid irradiation; the causes of death were acute myocardial infarction (1 patient), pulmonary embolism (1 patient), and rheumatoid lung disease complicated by respiratory infection (2 patients). After therapy, patients exhibited a prolonged reduction in the number and function of circulating T helper cells.