Left main pseuodaneurysm is a rare entity and is one of the potentially lethal consequences of coronary artery dissection. We describe a case of a young woman who almost a week after her delivery developed spontaneous left main dissection, manifested as acute anterior myocardial infarction. Left on medical treatment alone over a month, spontaneous dissection progressed to symptomatic large left main pseuodaneurysm, which was treated percutaneously with covered stents. © 2011 Wiley-Liss, Inc.