Between January 1990 and January 1995, 37 children and young adults with univentricular hearts were evaluated for total cavo-pulmonary connection (TCPC) or partial cavo-pulmonary connection (PCPC). Nineteen patients had tricuspid atresia, ten double-inlet left ventricle, five mitral atresia, and three had other complex univentricular lesions. Twenty-eight patients had previously been palliated by a systemic-pulmonary artery shunt or by pulmonary artery banding. All patients underwent physical examination, two-dimensional echo-cardiography, and cardiac catheterization. Suitability for TCPC was decided according to the modified Choussat criteria. Nine patients (24%), were judged unsuitable for any type of cava-pulmonary connection. Seventeen patients aged 5 (2-20) years underwent TCPC, and two patients awaited TCPC at follow-up (October 1995) Nine patients aged 10 (1-40) years had borderline morphology or haemodynamics and therefore underwent PCPC. One of these had, however, to be taken down immediately due to development of superior vena cava syndrome. The postoperative follow-up time was 20 (0.3 5.4) years. The 30-day, 1-, and 5-year survival rates (Kaplan-Meier) were 82%, 76%, and 76% after TCPC and 100%, 100%, and 100% after PCPC. All deaths were due to ventricular failure. At latest follow-up, all hospital survivors were in NYHA class I or II. All PCPC, and 85% of the TCPC patients were in sinus rhythm. All patients had good ventricular function. TCPC and PCPC can be performed in selected patients with univentricular hearts with an acceptable mortality and morbidity and result in significant functional improvement.