Background - Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC) is associated with ventricular arrhythmias (VA) and sudden cardiac death (SCD). A model was recently developed to predict incident sustained VA in ARVC patients. However, since this outcome may overestimate the risk for SCD, we aimed to specifically predict life-threatening VA (LTVA) as a closer surrogate for SCD. Methods - We assembled a retrospective cohort of definite ARVC cases from 15 centers in North America and Europe. Association of 8 pre-specified clinical predictors with LTVA (SCD, aborted SCD, sustained or ICD treated VT>250 bpm) in follow-up was assessed by Cox regression with backward selection. Candidate variables included age, sex, prior sustained VA (≥30s, hemodynamically unstable or ICD treated VT; or aborted SCD), syncope, 24-hour premature ventricular complexes (PVC) count, the number of anterior and inferior leads with T-wave inversion (TWI), left and right ventricular ejection fraction. The resulting model was internally validated using bootstrapping. Results - A total of 864 definite ARVC patients (40±16 years; 53% male) were included. Over 5.75 years [IQR 2.77, 10.58] of follow-up, 93 (10.8%) patients experienced LTVA including 15 with SCD/aborted SCD (1.7%). Of the 8 pre-specified clinical predictors, only 4 (younger age, male sex, PVC count and number of leads with TWI) were associated with LTVA. Notably, prior sustained VA did not predict subsequent LTVA (p=0.850). A model including only these 4 predictors had an optimism-corrected C-index of 0.74 (95% CI:0.69-0.80) and calibration slope of 0.95 (95% CI:0.94-0.98) indicating minimal over-optimism. Conclusions - LTVA events in patients with ARVC can be predicted by a novel simple prediction model using only 4 clinical predictors. Prior sustained VA and the extent of functional heart disease are not associated with subsequent LTVA events.