This prospective study evaluates the usefulness of clinical features and measurements of circulating immune complexes and autoantibodies for identification of patients with rheumatoid arthritis with a poor life prognosis. One hundred and seven hospital clinic patients, 64 with extra-articular manifestations, were followed up for a mean period of eight years, during which 50 deaths occurred. Comparison with an age and sex matched control population showed an increased incidence of deaths from myocardial infarction, pneumonia, and complications of rheumatoid arthritis. Patients with cutaneous ulcers, vasculitic rash, neuropathy, and scleritis had a higher mortality than patients whose disease was confined to the joints. Positive serological tests for precipitating antibodies to soluble cellular antigens and cryoglobulinaemia also predicted a poor prognosis. Eleven out of 12 patients (92%) with antibodies to soluble cellular antigens died compared with 21 out of 64 patients (33%) without antibodies. The presence of cryoglobulinaemia was associated with almost a twofold higher mortality. The laboratory measurements may reflect immunopathogenic mechanisms which lead to the occurrence of extra-articular disease features and reduce life expectancy.