The European Society of Cardiology (ESC) clinical risk model is reported in predicting sudden death of hypertrophic cardiomyopathy (HCM). We examined the validity of this model and investigated the significance of ejection fraction (EF) in predicting the prognosis using ESC risk model in HCM patients. 305 HCM patients (198 males) were followed (median follow-up 4.8 years) for life-threatening arrhythmic events (sudden death, aborted sudden death, sustained VT/VF, appropriate ICD intervention for VT/VF) and were divided using ESC risk model into low- (Group L), intermediate- (Group I) and high- (Group H) risk groups. There was a significant difference in the events rate among the 3 groups (L, 0.9%/year; I, 3.9%/year; H, 6.8%/year; log-rank p < 0.001) in all study patients. Reduced EF (<50%) was identified in 27 (8.9%) cases. There was a significant difference in the events rate among the 3 groups in patients with reduced EF (L, 2.4%/year; I, 4.9%/year; H, 16.1%/year; log-rank p = 0.025). There was a significant difference in the events rate among 2 groups in patients stratified as Group H (preserved EF, 3.1%/year vs. reduced EF, 16.1%/year; log-rank p = 0.041). ESC risk model precisely predicts life-threatening events in patients with HCM. Adding EF to ESC risk model are useful for further risk stratification of life-threatening arrhythmic events.