During the closure of the sternum, following the mitral valve replacement for mitral stenoinsufficiency, hemodynamic instability with cardiac tamponade was developed. After transfusion of massive diuretics and albumin for a few times, reclosure of the sternum was attempted with development of hemodynamic instability. And so we decided delayed sternal closure. After 72 hours of mitral valve replacement, delayed sternal closure was done with success, and so we report this case with literatures. [KTCS 1982;3:308-310]