Conduit stenosis is a major, albeit rare, complication following the Fontan palliation. A single-baffle conduit with polytetrafluoroethylene is widely used for an extracardiac type Fontan palliation. A polyethylene terephthalate conduit (Dacron) is sometimes used for the conduit when more flexibility is required. A Y-shaped conduit is rarely used, but it may reduce the energy loss and achieve better hepatic flow distribution. Data on the long-term patency and complications when using a Y-shaped Dacron conduit is lacking. We report a case of a severely stenotic Y-shaped Dacron conduit in a patient who underwent extracardiac Fontan palliation.