Four patients with chronic systemic lupus erythematosus (SLE) in whom myocardial infarction occurred at an unusually early age are described. The evidence suggests that the coronary occlusion was due to atherosclerosis. There was no evidence that active arteritis played any role. The only risk factor for atherosclerotic disease was hypertension. All patients had had both central nervous system and renal disease and had been taking corticosteroids for a minimum of 9 years. It is suggested that hypertension aggravated by chronic corticosteroid administration may be an important risk factor for atherosclerosis in patients with SLE.