A 12-year-old female with the Wolff–Parkinson–White syndrome underwent an electrophysiologic study followed by radiofrequency catheter ablation of the left-lateral accessory pathway. After several unsuccessful attempts, the procedure was stopped because of early recurrence of accessory pathway conduction. Twenty-four hours after the procedure, the patient was found without ventricular pre-excitation pattern on the electrocardiogram. During a 12-month follow-up, the Wolff–Parkinson–White pattern was no longer present. A transesophageal electrophysiologic study showed no further tachycardia induction and the patient is still asymptomatic. This report raises the issue that ablation-induced lesions may evolve considerably during the first few days after ablation, leading to either recurrent accessory pathway conduction or long-lasting complete cure.