Wolff-Parkinson-White (WPW) syndrome is characterized by classical electrocardiographic findings resulting from preexcitation of a part of the ventricular myocardium due to anomalous atrioventricular conduction via a accessory pathway. Anesthetic management with this syndrome is aimed at avoiding tachycardia and cardiac arrhythmia by using the techniques to avoid hypoxia, hypercarbia, acidosis and sympathetic stimulation. We experienced a case of severe hypotension and paroxysmal supraventricular tachycardia (PSVT) during insertion of subclavian vein catheter on a patient with this syndrome prior to operation, in spite of adequate anesthetic management. The patient's condition was recovered after infusion of adenosine and removal of catheter. Operation was postponed for further evaluation of WPW syndrome. After 3 days, electrophysiologic study was done and accessory pathway was ablated by radiofrequency catheter. After 6 days, the patient was operated uneventfully and discharged 2 weeks later. We report that minor stimulation such as central venous catheterization on a patient with WPW syndrome can cause life-threatening severe hypotension and PSVT.