A 31-year-old female patient was admitted to hospital with complaints of increased palpitation attacks. Delta wave,short PR interval and wide QRS wave were detected on ECG and the patient was diagnosed as Wolf Parkinson White syndrome (WPW). Electrophysiological study was performed. Accessory pathway in lateral region of the left free wall was determined. Radiofrequency ablation of accessory pathway was performed successfully. Electrophysiological study was repeated after accessory pathway ablation. There was no accessory pathway observed during the test, but atrioventricular nodal reentrant tachycardia (AVNRT) was induced. Slow pathway ablation with radiofrequency energy method was successfully performed. As a conclusion we may assume that it is important to show there will be no tachycardia induced especially the AVNRT after performing an ablation of accessory pathway in patients with WPW syndrome, Because one in ten patient with WPW syndrome is accompanied with AVNRT. Especially after successful ablation of accessory pathways, the ongoing complaints of palpitation may be caused by AVNRT.