The incidence of W-P-W syndrome is often noted in patients without other evidence of heart diseases. However, most of them wlll have supraventricular arrhythmias, characterized by paroxismal tachyarrhythmias. W-P-W- syndrome may be complicated by severe hypotension, syncope, congestive heart failure, atrial and/or ventrioular fibrillation and even sudden death, We experienced a case of W-P-W syndrome Immediately after induction of general anes-thesia on a patient with preoperatively normal ECG patterne and no evidence of otder heart disease.