A review of 51 patients who died while enrolled in a long-term prospective study of systemic lupus erythematosus (SLE) revealed that active SLE may persist or reappear late in the course of the disease. Vascular events, especially atherosclerotic coronary artery disease, occurred frequently. Moderate to severe atherosclerosis was seen in patients who had died of any cause after a prolonged duration of the disease and often contributed significantly to death. Diffuse proliferative glomerulonephritis, CNS lupus and major infections were indications of poor prognosis particularly early in its course.