During a 10-year period, 62 patients underwent the following modifications of the Fontan operation for repair of tricuspid atresia: direct atriopulmonary connection (N = 15), atriopulmonary connection using a conduit (N = 5), direct atrioventricular (AV) connection (N = 22), and AV connections with a valved conduit (N = 20), including 2 with combined Fontan-arterial switch procedures. The overall hospital mortality was 16.1% (10/62) (70% confidence limits, 11.2 to 22.4%). By multivariate analysis, the risk factors for early and late death included increasing right atrial pressure after repair, use of an atriopulmonary connection, and previous pulmonary artery banding (all variables, p less than 0.05). Postoperative catheterization was performed in 22 patients including 15 with AV valved-conduit connections. Right ventricular (RV) work based on pulmonary artery pressure minus right atrial pressure was correlated with the preoperative RV to left ventricular volume ratio computed from the four-chamber angiographic projection (p = 0.025), and was appreciable only with ratios exceeding about 30%. In 6 of 19 eligible patients, severe conduit obstruction has developed. Considering the survival data, the risk of reoperation, and postoperative hemodynamic findings, analysis of our experience supports the preferential use of nonvalved AV connections in most patients with tricuspid atresia and ventriculoarterial concordance.