Objectives The aim of this study was to describe the safety and outcomes of alcohol septal ablation (ASA) in younger patients with obstructive hypertrophic cardiomyopathy. Background The American College of Cardiology Foundation/American Heart Association guidelines reserve ASA for older patients and patients with serious comorbidities. Data on long-term age-specific outcomes after ASA are scarce. Methods A total of 1,197 patients (mean age 58 ± 14 years) underwent ASA for obstructive hypertrophic cardiomyopathy. Patients were divided into young (≤50 years), middle-age (51 to 64 years), and older (≥65 years) groups. Results Thirty-day mortality and pacemaker implantation rates were lower in young compared with older patients (0.3% vs. 2% [p = 0.03] and 8% vs. 16% [p < 0.001], respectively). Ninety-five percent of young patients were in New York Heart Association functional class I or II at last follow-up. During a mean follow-up period of 5.4 ± 4.2 years, 165 patients (14%) died. Annual mortality rates of young, middle-age, and older patients were 1%, 2%, and 5%, respectively (p < 0.01). Annual adverse arrhythmic event rates were similar in the 3 age groups at about 1% (p = 0.90). Independent predictors of mortality in young patients were age, female sex, and residual left ventricular outflow tract gradient. Additionally, young patients treated with ≥2.5 ml alcohol had a higher all-cause mortality rate (0.6% vs. 1.4% per year in patients treated with <2.5 ml, p = 0.03). Conclusions ASA in younger patients with obstructive hypertrophic cardiomyopathy was safe and effective for relief of symptoms at long-term follow-up. The authors propose that the indication for ASA can be broadened to younger patients.