Direct cavopulmonary connection using an extracardiac conduit has theoretical advantages in the management of children with single ventricles. Completion of a Fontan procedure using an extracardiac conduit may be accomplished without the use of cardiopulmonary bypass (CPB). Experience with the first 15 consecutive patients in whom CPB was not used in completion of a Fontan procedure is reported. From January 1995 to July 1997, 15 patients had an extracardiac inferior vena cava-to-pulmonary artery conduit constructed without the use of cardiopulmonary bypass. Eleven of these 15 patients had hypoplastic left heart syndrome, whereas the remaining four had tricuspid atresia. Average age was 24 months, ranging from 18-34 months. Average weight was 11 kg, ranging from 8.6-12.4 kg. Risk factors identified included elevated pulmonary vascular resistance in one patient with hypoplastic left pulmonary artery, at least moderate atrioventricular valve regurgitation in 3 patients. An inferior vena cava-to-atrial shunt was used during construction of the cavopulmonary conduit. A single 4-mm fenestration was used. Postoperatively, there were no mortalities. One patient with hypoplastic left heart syndrome and at least moderate tricuspid valve regurgitation was overdosed with Digoxin. He required prolonged resuscitation for intractable ventricular dysrhythmia. Complications in others include one mediastinitis, and superficial wound infection in a second. Pleural effusions persisted in 2 of 15 patients two weeks after surgery. Excluding the one patient who had ventricular dysrhythmia from Digoxin overdose, the average ICU stay was 3 days (range, 1-6 days). Length of hospital stay was 13 days (range, 4-38 days). The average number of ventilator hours was 14 following surgery (range, 1-72 hours). There has been no late death. In conclusion, completion of a Fontan procedure using an extracardiac conduit without cardiopulmonary bypass may be achieved with acceptable results. In the last 7 patients the average hospital length of stay was 7 days with an ICU stay of 3 days. Whether this method has any advantage over more conventional ones using cardiopulmonary bypass remains to be proven.