Congenital long QT syndrome (LQTS) is a rare genetic ion transmembrane disorder that has been associated with multiple various genetic mutations including life-threatening cardiac arrhythmias and sudden death. Left thorascopic sympathectomy is an effective treatment for patients who are refractory to medical therapy or who need frequent epicardial internal cardiodefibrillator intervention. Although there is substantial literature about this therapy in adults, few reports detail the outcomes in children who undergo left thorascopic sympathectomies to treat LQTS. The authors report the successful use of a left thoracic sympathectomy for the treatment of an 11-year-old girl who had persistently symptomatic LQTS, even after implantation of an automatic cardioverter-defibrillator. The patient remained clinically stable without arrhythmias through 6 months' of follow-up. The authors also reviewed the relevant literature and found that it suggests that 77% of patients will have immediate resolution of their symptoms/arrhythmias after the procedure. When the outcome definition was broadened to include patients who had only 1 or 2 cardiac episodes in the follow-up period, 88% of cases were considered successful. The results of this case study and literature review suggest that left thorascopic sympathectomy is a safe and effective approach for treating pediatric patients with LQTS.