A case with the giant aneurysm of the ductus arteriosus combined with severe mitral regurgitation is reported. 58-year-old male underwent MVR and patch closure of the ductal orifice for staged operation. The first operation was MVR and patch closure of the PDA orifice of the pulmonary artery end using retrograde cerebral perfusion (RCP) with deep hypothermic circulatory arrest (DHC). The second operation was performed on 3 months after the first operation using left thoracotomy approach, and patch closure of the ductal orifice via the aorta using RCP with DHC was performed. Upon following-up examination, the patient is now doing well 20 months after the initial surgery.