The most common cause of portal hypertension in children with healthy livers is the prehepatic block. A 7-year-old girl had presented with portal vein thrombosis after umbilical vein catheterization in the newborn period. She suffered from collateral circulation with recurrent bleeding episodes due to esophageal varices (stage III-IV) and developed hypersplenism. Ultrasound demonstrated an open branch of the left portal vein. Direct splenoportography showed an open and communicating superior mesenteric vein. Liver biopsy was normal. An autologous left jugular vein graft was used to create a bypass from the superior mesenteric vein to the umbilical portion of the left intrahepatic portal vein (mesentericoportal Rex-shunt). Postoperatively, normal intrahepatic portal vein flow was demonstrated by ultrasound. After 2 years of follow-up, the patient is asymptomatic with no signs of portal hypertension. In contrast to classic portosystemic shunt operations, this bypass restores physiological portal vein flow, thus avoiding the possible consequences of longterm portosystemic shunting and low-grade encephalopathy.