Current guidelines recommend an implantable cardiac defibrillator (ICD) in patients with symptomatic heart failure and reduced ejection fraction (HFrEF; left ventricular ejection fraction LVEF ≤35%) despite ≥3 months of optimal medical therapy. Recent observations demonstrated that sacubitril/valsartan induces beneficial reverse cardiac remodeling in eligible HFrEF patients. Given the pivotal role of LVEF in the selection of ICD candidates, we sought to assess the impact of sacubitril/valsartan on ICD eligibility and its predictors in HFrEF patients. We retrospectively evaluated 48 chronic HFrEF patients receiving sacubitril/valsartan and previously implanted with an ICD in primary prevention. We assumed that ICD was no longer necessary if LVEF improved >35% (or >30% if asymptomatics) at follow-up. Over a median follow-up of 11 months, sacubitril/valsartan induced a significant drop in LV end-systolic volume (-16.7 ml/m2, p=0.023) and diameter (-6.8 mm, p=0.022), resulting in a significant increase in LVEF (+3.9%, p<0.001). As a consequence, 40% of previously implanted patients resulted no more eligible for ICD at follow-up. NYHA class improved in 50% of the population. A dose-dependent effect was noted, with higher doses associated to more reverse remodeling. Among patients deemed no more eligible for ICD, lower NYHA class (odds ratio (OR) 3.73 95% CI 1.05; 13.24, p=0.041), better LVEF (OR 1.23 95% CI 1.01; 1.48, p=0.032) and the treatment with the intermediate or high dose of sacubitril/valsartan (OR 5.60 1.15; 27.1, p=0.032) were the most important predictors of status change. In symptomatic HFrEF patients, sacubitril/valsartan induced beneficial cardiac reverse remodeling and improved NYHA class. These effects resulted in a significant reduction of patients deemed eligible for ICD in primary prevention.