Long QT Syndrome is characterized by syncope and fatal ventricular arrhythmia. Monotherapy with beta blockers is the first-line therapy. In patients with recurrent syncope despite therapy with beta blockers, combinations of the following modalities of treatment may be considered: pacemakers, left cervicothoracic sympathectomy, and implantable cardioverter defibrillators. Recently, we anesthetized a patient with Long QT Syndrome who underwent thoracoscopic left upper ganglionectomy for recurrent episodes of syncope and ventricular arrhythmia despite aggressive use of propranolol. Because of the increased risk of developing fatal ventricular arrhythmias during anesthesia and surgery, we performed a left stellate ganglion block prior to induction of anesthesia to prevent the ventricular arrhythmia that may be triggered by stimulation of the sympathetic nervous system and to assess the effect of surgical ganglionectomy on the QT interval. Following the block, the QT interval was shortened, and anesthesia and surgery was uneventful though anesthetic induction caused serious sympathetic responses. We recommend a left stellate ganglion block prior to induction of anesthesia in patients with Long QT Syndrome resistant to beta blocker to prevent fatal arrhythmia and to predict the efficacy of the surgical sympathectomy on the QT interval.