Spontaneous coronary artery dissection (SCAD) is an uncommon condition that may lead to sudden coronary artery occlusion resulting in a fatal acute myocardial infarction. It usually affects young to middle age women. A Medline search from 1966 to 2001 (using keywords: coronary artery dissection and systemic lupus erythematosis) revealed no prior reports of coronary dissection in a patient with systemic lupus erythematosis (SLE). We describe a 48-year old woman with SLE who sustained a fatal spontaneous left main coronary artery dissection. Coronary angiogram was notable for marked variability in the size of coronary lumen from systole to diastole. This case demonstrates the need to consider SCAD in the evaluation of chest pain and myocardial infarction in patients with SLE. Furthermore, in the absence of classical angiographic findings of coronary dissection, a detailed review of phasic changes in coronary lumen during a cardiac cycle could help reach this diagnosis.