This is a case report of 8-years-old boy, who was diagnosed mitral regurgitation, secundum type of atrial septal defect and annulo-aortic ectasia in association with Marfan syndrome. His diagnosis was confirmed at the age of 6 years when cardiac catheterization was carried out. Atrial septal defect was closed using PTFE patch (0.2 mm in thickness). His diseased mitral valve was replaced with CarboMedics prosthesis 27 mm in diameter. Because of intact aortic valvular function, we left the ectatic aorta alone at present time for future procedure. His postoperative course was uneventful. He is active and doing well at present and has been followed-up at the outpatient clinic routinely. He might be having to require AVR and graft implantation for ectatic ascending aorta.