To examine the mid term outcome of the lateral tunnel Fontan and the result is to be compared to extracardiac Fontan operation. Between March 1991 and May 2002, 72 lateral tunnel (LT) and 28 extracardiac conduit (EC) total cavopulmonary connection (TCPC) were performed. Right atrium was incised parallel to the sulcus terminalis and LT was created by using autologous right atrial wall. Lateral tunnel size was determined 1-2 mm larger than normal half pulmonary artery (PA) size according to the body weight. There were 1 early and 1 late death, both initial LT group. Supraventricular tachycardia was found in 1 patient with EC group and 4 in LT group (all heterotaxy syndrome). There were no differences in mortality and mobidity between LT and EC TCPC. Lateral tunnel TCPC is useful especially to small infants and children.