Treatment of chronic atrial fibrillation with intraoperative radiofrequency ablation is gaining more acceptance in patients with rheumatic valve disease. This article reports a case of fatal atrio-esophageal fistula after radiofrequency ablation in a patient with rheumatic mitral and aortic valve disease with chronic atrial fibrillation. (C) 2003 by The Society of Thoracic Surgeons.