We herein report the two adult patients hardly predictable sudden cardiac arrest caused by presumed Kawasaki disease (KD). Case 1: A 29- year-old man who had a history of KD at 10 months of his age complicated with bilateral giant coronary aneurysms, and was received a surgery of coronary artery bypass grafting (CABG) when he was 17 years old. He was transferred to emergency center because of sudden cardiac arrest during live concert and revived by automated external defibrillator (AED). Case 2: A 26-year-old man with a history of KD at 1year old of his age, complicated with bilateral giant coronary aneurysms, and was received a catheter intervention of rotational atherectomy (ROTA) to left anterior descending (LAD) artery at 16 years old of his age. He suddenly fell with ventricular fibrillation (VF) on playing futsal, and was hospitalized after revival by AED. Both of them had past history of myocardial infarction (MI) in their youths, however, did not have left ventricular dysfunction, symptomatic arrhythmia, and evidence of acute MI at admission. Therefore, it was difficult to strongly predict possibility of fatal arrhythmia in these cases. Finally, they received the second CABG’s for each after stabilizing and returned to their daily lives. It had been rarely reported a fatal arrhythmia in asymptomatic KD patients with normal left ventricular function with revival with recent spread of life support with public access of defibrillator. Our experiences may suggest one style with a paradigm shift in management of patients with coronary artery complications at the remote period of KD.