BackgroundLeft atrial auricle (LAA) clipping is a common method of preventing cardiogenic thromboembolism. However, acute coronary syndrome (ACS) has been reported as a fatal complication of LAA clipping. We describe a case of ACS 2 months after LAA clipping.Case presentationA 33-year-old male with atrial fibrillation was scheduled LAA clipping during aortic valve replacement for congenital aortic bicuspid valve. The surgery went smoothly with no postoperative complications, but he suddenly went into cardiac arrest 2 months later. Emergency coronary angiography and intravascular ultrasonography revealed that compression by the clip of the left main coronary trunk had caused the ACS. Percutaneous coronary intervention with stents was performed, and the clip was removed under general anesthesia.ConclusionEven in the remote timepoint of LAA clipping, compression of the coronary artery by the clip should be differentiated as a cause of ACS.