In order to evaluate possible changes in the portal venous system after endoscopic sclerosis of esophageal varices, 25 cirrhotic patients underwent abdominal ultrasonography before the first session of sclerotherapy and after eradication of esophageal varices had been achieved. The caliber of the portal, splenic, and superior mesenteric veins was measured sonographically in each case. Sonographic results were compared statistically before and after sclerotherapy. Neither evidence of significant variations in the caliber of the portal veins nor thrombotic obliteration was seen. These results support the view that sclerotherapy has no significant negative side effects on the portal venous system.