Aneurysmal aortic pouch is quite a rare finding in echo cardiographic examinations. We present a case with aneurysmal pouch on non-coronary cusp detected by both transthoracic and transesophageal echocardiography and confirmed by surgery. The lesion invaded the interventricular septum and required septal repair in addition to aortic valve replacement during surgery. We consider that catheter injury was the most likely aetiology for the aneurysmal aortic pouch because the patient had previously undergone left ventricular catheterization.