We successfully treated two rare cases of coronary aneurysm with fistula. Case 1;A 65-year-old female referred to our hospital with the coronary aneurysm and fistula. Right coronary aneurysm with fistula leading to coronary sinus was observed. Coronary bypass surgery using a saphenous vein to #4PD was performed, and two right ventricle branches were reconstructed. Coronary aneurysm was resected. Case 2;A 46-year-old male was admitted with chest discomfort. Coronary aneurysm with fistula from the left main trunk to left ventricle was demonstrated. Ligation of the coronary artery aneurysm and suture closure of the entry site to the left ventricle was performed. Both patients had uneventful recovery.