Increased portal pressure is the product of both increased resistance to splanchnic flow through the liver and increased blood flow in the portal circuit. Although portal hypertension in children is less common than in adults, the important clinical end results are the same, ie, esophageal variceal hemorrhage, ascites, and hypersplenism. The etiology of portal hypertension in children is very different from adults in whom cirrhosis (most commonly secondary to alcohol) is the predominant cause. In children, extrahepatic obstruction due to portal vein thrombosis is the most common cause. However, as children survive longer with biliary atresia, cystic fibrosis, and other liver diseases, the incidence of intrahepatic obstruction causing portal hypertension is increasing. The treatment has also undergone a dramatic evolution over the last decade with the near extinction of portosystemic shunt procedures and their replacement with endoscopic treatment of esophageal varices and liver transplantation.