OBJECTIVE Analysis of mortality and morbidity of patients treated by primary total cavopulmonary connection (TCPC)-Primary correction group, and comparison to patients treated by bidirectional Glenn (BDG) followed by total cavopulmonary connection-two stage TCPC group. METHODS Retrospective study of 123 consecutive patients who underwent 144 different types of cavopulmonary connections between 1987-1995: bidirectional Glenn 59, HemiFontan operation 10, primary total cavopulmonary connection 54, and total cavopulmonary connection completion after previous bidirectional Glenn 21. Important preoperative risk factors: age, systemic outflow obstruction, pulmonary venous obstruction, pulmonary artery (PA) hypoplasia (McGoon ratio), PA stenosis/distortion, PA mean pressure, PA vascular resistance, atrioventricular valve regurgitation, systolic and diastolic ventricular function and ventricular hypertrophy were re-evaluated according to Texas Heart Institution Scoring System in both groups. Three different preoperative risk groups were established: low risk, score (0-3) moderate risk (4,5) and high risk score (> or = 6). RESULTS Mean age was 85.2 month (range 16.1-229.5 months) and 106.6 months (range 42.6-178.9 months) in primary correction group and two stage TCPC group, respectively. Diagnosis was similar in both groups, majority having univentricular heart or hypoplastic one ventricle. Initial palliation (pulmonary artery banding, modified aortopulmonary shunt, coarctation repair etc.) was performed in 38 (70.3%) patients of primary correction group and in 12 (57.1%) two stage TCPC group. The mortality was 7.4% (4 out of 54) and 14.2% (3 out of 21) for primary correction and two stage TCPC group, respectively. There were two take down in the primary correction group. There was no late death in either group. Operative data and postoperative morbidity did not statistically differ in both groups. CONCLUSIONS Until 1993 bidirectional Glenn was preferred to primary total cavopulmonary connection for high risk patients. High mortality 14.2% patients of two stage TCPC group vs. 7.4% of primary correction group in patients with the same preoperative hazard led us to change our policy. We now prefer primary TCPC for all patients with functional single ventricle and surgically correctable major associated defects. High risk patients undergo TCPC with fenestration. Patients not suitable for TCPC undergo either HemiFontan operation or some type of initial palliative procedure.