The Authors present and discuss clinical and therapeutic aspects of several cases of chronic portal thrombosis, troncular and radicular, either isolated or variously associated. Splenoportography and selective arteriography do not always provide a clear-cut picture of the vascular situation, particularly in the presence of mural thrombi. Surgery may be needed as an emergency measure in cases of hemorrhage, but the best results are obtained if it can be done electively. Indications, however, must be evaluated very carefully in each individual case, especially for thrombosis not associated with cirrhosis of the liver, in which the tendency to a more favorable natural evolution may invite a more conservative approach. The choice of surgical procedures is dictated essentially by the site of obstruction in the portal system. After discussing the indications for various methods, the authors present some cases of thrombosis involving only the superior mesenteric vein, managed successfully by disobliteration and mesenterocaval anastomosis.