A 73-year-old woman was diagnosed with coronary artery aneurysms associated with coronary-pulmonary arterial fistula in a preoperative examination for transverse colon cancer. One of the aneurysms (28 mm) originated from a branch of the right coronary artery and the other two (16 and 12 mm) originated from a branch of the left coronary artery. We performed surgery to prevent their rupture because the right coronary artery aneurysm showed a tendency to enlarge. Surgery was performed through a median sternotomy under cardiopulmonary bypass. Suture closure of the inflow and outflow of the aneurysm was performed. The coronary-pulmonary arterial fistula was ligated. In addition, suture closure of the outflow of the coronary-pulmonary artery fistula into the pulmonary artery was performed, under direct view after incision of the pulmonary trunk. No residual shunt blood flow in the coronary-pulmonary arterial fistula was observed on postoperative echocardiography. Furthermore, no coronary aneurysm and coronary-pulmonary arterial fistula was recognized on postoperative coronary computed tomography. The patient made an uneventful recovery and was discharged from the hospital on postoperative day 12.