Background: The elderly WPW patients are expected to have different clinical and electrophysiolgic (EP) characteristics from younger WPW patients. This study was performed to evaluate the characteristics of elderly WPW syndrome and the influence of age on WPW syndrome. Methods: The 562 WPW patients (372 male, 37.4짹15.1 years) who had underwent EP study from 1997 to 2006 in a tertiary referral center were evaluated retrospectively. An elderly group of 125 patients (> 50 years) were compared with a younger group of 437 patents (��� 50 years). Clinical presentation and EP variables were compared between groups. Results: Among documented tachycardia, the incidence of atrial fibrillation (AF) were higher in elderly group than younger group (29% vs 19%, p = 0.05). The shortest atrial and ventricular pacing cycle length with 1:1 conduction via the bypass tract, anterograde and retrograde effective refractory period (ERP) of the bypass tract was longer in elderly groups than younger age group. Atrial and ventricular EPR of elderly group was longer than that of younger group. Success and recurrence rate of radiofrequency ablation was not different between groups. In 121 patients with initial presentation of WPW with AF, recurrence rate of AF was higher in elderly group than younger group (6% vs 19%, p = 0.04) during mean follow up period of 457 days. Conclusion: Although the elderly WPW group had more benign EP characteristics, the incidence of AF was higher compared with the younger group. Thus the management of WPW syndrome in elderly patients should be as aggressive as in the younger patients including follow up for recurrence of AF.