This report describes a rare case of the fistula between the non-coronary sinus and the right atrium (RA) after ascending aortic replacement for chronic aortic dissection. A 67-year-old lady had been suddenly suffering from severe dyspnoea with general fatigue for a couple of days. Trans-thoracic echocardiogram in the emergency room demonstrated massive shunt flow from the non-coronary sinus to the RA with remarkable dilatation of the RA, right ventricle (RV) and inferior vena cava, similar to the rupture of sinus of Valsalva (Konno-type IV). The fistula was successfully treated by partial remodelling of the aortic root in an emergency basis because of her life-threatening illness. Some remaining diseased aortic root, which may be related to initial dissection or inappropriate use of gelatin–resorcin–formalin glue at the previous ascending aortic replacement, may cause this kind of serious events. Modified aortic root remodelling method with only diseased sinus resected was successfully applied to the localised aortic root disorder.