The outcome was reviewed in 17 patients aged 15-40 years with tricuspid atresia and transposed great arteries selected by survival beyond age 14 years. Only five lead normal lives (ability index 1 or 2); the rest are dead or disabled. Arrhythmias occurred in seven. Maintenance of sinus rhythm is important because incessant atrial arrhythmias cause serious symptomatic deterioration. Pulmonary vascular disease and subaortic stenosis were important determinants of late mortality and morbidity. Because the mortality associated with the Fontan operation was high in these patients it should be performed with impeccable surgical technique and only in those who fulfil all the selection criteria for the operation. A shunt is the preferred option when any of the criteria are not met.