Seventy-four patients with heptaic fibrosis associated with Schistosoma mansoni infection were examined. The intrasplenic pressure measured by the percutaneous method had a direct linear relation with the portal pressure measured directly at operation and by the percutaneous transhepatic method. Hematemesis, esophageal varicosities and venous hum over the abdomen are indications of the level of the portal pressure. The size of the liver and spleen had no constant relation to the portal pressure. Ascites is frequently, but not always, associated with high pressures. Spleno-portal venography used in conjunction with intrasplenic pressure measurement is particularly valuable in diagnosis of portal hypertension and in demonstration of veins suitable for portocaval anatomosis.