Lateral tunnel modification of Fontan procedure (LTF) is widely practiced based on the advantages of better hydrodynamics and fewer atrial complications. We have routinely employed extra-cardiac conduit Fontan (ECCF) because of the following potential advantages: 1) it avoids the atrium completely in the Fontan path, 2) it can be performed on a perfused beating heart without cross clamping the aorta thereby completely avoiding ischemic insult to the myocardium, and 3) it provides improved laminar flow. From 7/92 to 8/94, 35 patients (pts) aged 1.7 to 44.2 years (median 6.52 years) underwent ECCF, including revision of a failing Fontan to ECCF in 7 pts. Principal diagnoses were tricuspid atresia (n: 14), double inlet ventricle (n: 10), corrected transposition of the great arteries (SLL) with left atrioventricular valve atresia (n:4) and other forms of single ventricle in the rest (n:7). An avenge of 2.3 previous operations were done per patient. Surgical procedure included extracardiac total cavopulmonary anastomosis using a ePTFE conduit (16 to 22 mm) or a nonvalved aortic homograft conduit (18 to 25 mm). Pop off fenestration between the conduit and the atrium was provided by a 4 - 5 mm ePTFE tube graft (n:20) or a side to side anastomosis with the atrium In:4). Additional surgical procedures included ligation of systemic shunts (n: 17), pulmonary arterioplasty (n:15), enlargement of bulboventricular foramen (n:4), mitral valve repair (n:1), and cryoablation of junctional ectopic focus (n:1). The only early death in the series was a pt of a failing Fontan with chronic massive ascites, pleural effusions, and cachexia who was not a candidate for heart transplant due to social reasons. Early complications included prolonged pleural and/or pericardial effusion in 6/34 pts (18%) and transient arrythmias in 6 pts. Permanent pacemaker was implanted in 4 pts: 2 pts with pre-existing CHB and 1 pt following VSD enlargement and 1 pt with SLL. At a folloW-up of 1 to 22 months (median 11) there were no significant new arrythmias, one pt required reoperation for thrombosis of left pulmonary artery and 3 pts required pericardioperitoneal window for effusion, and one pt died following re-do sternotomy. ECCF is an excellent alternative to LTF with good early and midterm results. However, late follow up is essential to evaluate its potential advantages.