Postoperative Fontan patients can develop hemodynamic abnormalities and refractory atrial arrhythmias resulting in significant morbidity and mortality. We present our experience with total cavopulmonary artery conversion and arrhythmia surgery. Between 1994 and 2001, 41 patients underwent total cavopulmonary artery conversion and arrhythmia surgery. Significant hemodynamic lesions were repaired concomitantly: aortic aneurysm (n=1), atrioventricular valve insufficiency (n=8), and pulmonary artery stenosis (n=9). Thirty-five patients were in New York Heart Association class III or IV. Mean age at original Fontan was 7.5+/-6.5 years, at Fontan conversion, 18.7+/-9.0 years. Arrhythmia surgery for atrial re-entry tachycardia evolved from isthmus cryoablation (n=10) to right-sided maze (n=17). Maze-Cox III was used for 14 patients with atrial fibrillation. Atrial (n=34) and dual chamber (n=5) pacemakers were placed. Mortality and reoperation for bleeding rates are 0%. Chest tubes were removed on postoperative day 9.0+/-6.0. Mean hospital stay was 11.8+/-6.6 days. Three patients required cardiac transplantation at 8 days, 9 months, and 33 months postoperatively. There was one long-term death from acute myocardial infarction 2 years postoperatively. For the entire series, arrhythmia recurrence is 12.2% (5/41). Only 9.8% of patients (4/41) receive chronic antiarrhythmic medications; these patients were among the first eight in the series. Most patients are in New York Heart Association I or II. Bruce protocol in 12 patients showed increased tolerance (P<.05) Total cavopulmonary artery conversion with concomitant arrhythmia surgery is excellent therapy for patients with failed Fontan. It is safe, improves New York Heart Association class, improves exercise tolerance, and the incidence of recurrent arrhythmias is low.