Background:. We retrospectively reviewed our experience with 123 patients who underwent the extracardiac conduit Fontan procedures(ECC) between November 1996 and November 2002. Method: There were 53->42 patients(43.1% ->34.1% ) of left (n=22) and right(n=31->20) isomerism. Previous procedures included PAB(n=20), modified BT-shunt(n=29), BCPS(n=92), TCPS(n=11), others(n=6) and none(n=14). Mean intervals between BCPS or TCPS and ECC were 19.1 and 39.9months. Median age, weight at Fontan procedure were 34.5months, 14.0Kg. The means of PVR and PAP were 1.54짹0.67 WU and 12.43짹3.18mmHg. In 16 patients, atrioventricular valve regurgitation(AVVR) operation was combined. Aortic cross-clamp was avoided in 72 patients. A 14- to 24-mm flexible Gortex tube graft(n=103), Hemashied graft(n=18) or alternatively was used. Fenestration were created in risky Fontan candidates(n=64). The incidence of fenestration has decreased significantly over the course of our experience. Results: Mean follow-up period was 31.7months. There were 3cases(2.4%) of early hospital mortality and no mortality from Jun 2000. There was no significant difference of morbidity and mortality between in AVVR group and in non-AVVR group. New arrhythmia developed in 8cases(6.89%) of 116 preoperative NSR patients during follow-up period: preoperative arrhythmia(n=7), immediate postoperative arrhythmia(n=20), follow-up period arrhythmia(n=14). There were 1 case of Gortex conduit thrombosis due to protein C deficienty and 1 case of Hemashield conduit obstruction by severely thickened endothelial peel. Conclusion: The extracardiac Fontan procedure provides good early and midterm results and low incedence of new developed arrhythmia and conduit complicatioins.