We successfully treated a case of a 2-year-old male with aortic coarctation coexisting with severe mitral regurgitation via left posteriolateral thoracotomy at one stage. After a mitral valve replacement under perfused ventricular fibrillation with moderate hypothermia, we repaired the aortic coarctation with coarctation resection and end-to-end anastamosis with the aid of deep hypothermic circulatory arrest and selective low-flow cerebral perfusion. The patient had an uneventful hospital course and remains well.