Coronary aneurysm is a rare condition, reported in only 1.2-4.9% of patients who have undergone coronary artery bypass grafting (CABG) [1]. We report a rare case of multiple coronary and cerebral artery aneurysms, and discuss the pathological findings. Case report A 73-year-old man presented with acute myocardial infarction on the day before surgery for multiple cerebral aneurysms. Electrocardiography revealed ST-segment elevation in leads V5 and V6. Laboratory findings showed high creatine phosphokinase, creatine phosphokinase-MB, and lactate dehydrogenase levels at 1194, 254, and 389 U/L, respectively. Emergent coronary angiography revealed that the lesion that caused the myocardial infarction was at the distal left circumflex artery (Video 1). Huge coronary aneurysms were also found in the left circumflex artery. Computed tomography (CT) revealed saccular aneurysms with external diameters of 38 and 35 mm, respectively (Fig. 1A, Video 2).