Three patients, 24, 24 and 25 years of age, with systemic lupus erythematosus had signs of myocardial infarction. Two had serial electrocardiographic changes indicative of infarction without any cardiac symptoms. The third patient had clinical evidence of an acute massive myocardial infarction, which was proved at autopsy to be due to coronary atherosclerosis. This case is presented in detail and the association between systemic lupus erythematosus and myocardial infarction is reviewed. It is postulated that the relation between lupus erythematosus and coronary atherosclerosis is more than coincidental.