Methods: Retrospective case series studyResults: 111 HFMD with severe complication consisted of grade 3 (54.1%), grade 4 (45.9%), mean age of 24.6 months old, most of them under 3 years (91.9%). Respiratory complication requiring mechanical ventilation accounted for 68.4%, cardiovascular complication included cardiopulmonary collapse, systemic arterial hypertension (44.1%), especially 3 cases (2.7%) developed ventricular tachycardia (VT), ventricular fibrillation (VF).