We describe a 41-year-old woman who presented with acute ST-segment elevation myocardial infarction. Emergent percutaneous intervention was performed with aspiration thrombectomy followed by coronary artery stenting. White material was extracted from the aspiration catheter. Reperfusion therapy after stenting was successful. After undergoing a cardiac rehabilitation program, she was discharged from hospital on day 10. Pathological examination revealed that the aspirated material consisted of normal vascular components including endothelial and smooth muscle cells. Aspiration thrombectomy is a commonly used procedure with a low complication rate. This case presents the previously unreported complication of coronary artery injury.