Abernethy malformation, also known as congenital extrahepatic portosystemic shunt, is a rare malformation in which the intestinal and splenic venous blood bypasses the liver and drains into systemic veins through a complete or partial shunt.  This congenital anomaly may present in children or in adults and are often found following abdominal imaging that was ordered for other reasons.  Clinical presentation may include neurodevelopmental, hepatic, and cardiopulmonary manifestations.  Portosystemic encephalopathy and gastrointestinal bleeding occur only occasionally.  The decision to provide an intervention to close the shunt should be based on the presence of deleterious clinical manifestations.  Current therapeutic options include interventional radiology embolization or closure devices, surgical ligation and liver transplantation.