Percutaneous transhepatic portography with selective catheterization of the portal vein and its tributaries was performed on 120 patients, of whom 71% had cirrhosis of the liver. The technique was improved by ultrasonically guided puncture, and the procedure was successful in 96% of the examinations. Collateral veins were visualized in 81% and esophageal or gastric varices in 69% of the patients with portal hypertension. The procedure was performed with little risk and discomfort, and portograms of high quality were obtained. Other applications of percutaneous transhepatic catheterization of the portal vein system are discussed.