Cardiac sympathetic denervation (CSD) is a surgical option for patients with life-threatening ventricular arrhythmias. Previously described cohorts included populations in which CSD was performed for primary and secondary prevention. We report the efficacy of CSD as adjunct therapy in children with medically refractory life-threatening arrhythmias. Retrospective review of patients undergoing thoracoscopic CSD at one institution between January 2008 and July 2017. Patient demographics, indications, procedural details, complications, length of stay, and effectiveness were evaluated. Ten thoracoscopic CSD procedures were performed in 8 patients. Mean age was 8.2 years (8 days-19 years); mean weight was 32.6 kg (2.7-57 kg); and 50% were female. Four had long QT syndrome, 3 catecholaminergic polymorphic ventricular tachycardia, and 1 short QT syndrome. All patients had at least two (2 to >40) episodes of resuscitated ventricular arrhythmia and were maximized on medical therapy. Six patients had implantable cardioverter-defibrillators (ICD) with a mean of 11.9 appropriate discharges (1-40) before CSD. All patients underwent left CSD; 2 subsequently required right CSD. Four of the 6 ICD patients experienced dramatic improvement (total 48 ICD discharges pre-CSD; 3 post-CSD). Two patients noncompliant with medical therapy had no significant improvement (24 ICD discharges pre-CSD; 23 post-CSD) and also underwent right CSD, again with no improvement (23 discharges pre-right CSD; 28 post-right CSD). Thoracoscopic CSD can be safely performed in the neonate and pediatric populations. When utilized with medication therapy, CSD is an effective adjunct in reducing ICD discharges and arrhythmias.