The purpose of this retrospective study was to determine the outcome of patients who underwent a Fontan procedure at National Heart Institute "Ignacio Chávez", Mexico, from January 1989 to December 2003. We had 81 patients with a mean age of 7 years old: 53 with tricuspid atresia, 14 with pulmonary atresia and intact septum, 11 with univentricular atrioventricular connection and 3 with Ebstein's anomaly. An intra-atrial tunnel was performed on 61 patients and an extracardiac conduit on the rest. Of all, 53 underwent a fenestration. The surgical mortality was 13% for tricuspid atresia and 25% for the other diseases. We had an overall mortality of 28.4%, being the main causes cardiogenic shock and arrhythmia. The global survival was 71% in 55 months of following. Takedown was indicated on 5 patients. The patients without fenestration showed to have 2.8 times more risk of death. The mean pulmonary artery pressure > or = 20 mmHg plus the left atrium pressure > or = 10 mmHg increased the death risk 3.6 times. Of the 52% who required readmission, the main causes were hemodynamical failure and infections. The more relevant complications were: arrhythmia (38%), protein-losing enteropathy (8%) and thrombotic cerebral events (1.4%).