Coronary artery ectasia (CAE) is a rare condition defined as the dilatation of coronary artery to at least 1.5 times larger than the normal adjacent coronary artery. Clinical manifestations of CAE vary, ranging from asymptomatic to ST-segment elevation myocardial infarction (STEMI). Because of its rarity and clinical diversity, the best treatment strategy and prognosis for CAE remain unclear. We describe a case of STEMI caused by intracoronary thrombus formation within an ectatic area in a patient with liver cirrhosis (LC). The patient was successfully managed by thrombus aspiration only, without balloon angioplasty or stent implantation, and maintained by dual antiplatelet therapy with aspirin and ticagrelor, a potent new P2Y12 inhibitor.