The authors present the case of a 17 year old girl admitted to hospital for poor general state, mild scleral jaundice, deficient nutritional state, oliguria and massive ascites. She was diagnosed with Budd-Chiari syndrome: thrombosis of the left suprahepatic vein and nonocclusive thrombosis of the inferior vena cava at the level of the 12th thoracal and the lumbar vertebrae. The specific feature of the case was the association of portal and splenic vein thrombosis. A mesentericocaval shunt with external jugular grefon was performed. The evolution at 20 months after surgery has been favorable. She has no ascites, the nutritional state has normalized and hepatic laboratory findings have returned to normal values. There still persists a high consistency splenomegaly, but without hematological hypersplenism. Even though the mesentericocaval shunt is not without complications, it represents an efficient alternative for the treatment of Budd-Chiari syndrome, when endovascular techniques are not available.