Webs of hepatic veins have been rarely described. Two patients presented with intractable ascites in whom hepatic venography demonstrated this unusual finding. Liver biopsies from both patients showed variable patterns of perivenular fibrosis. Transvenous balloon dilatation of the web was effective in abolishing the pressure gradient across the obstruction and improving hepatic venous outflow. Both patients showed a dramatic clinical improvement following the procedure, with complete resolution of ascites in one patient and considerable improvement in the other with symptoms not recurring over 18 months of follow-up. The histological features that help to distinguish hepatic venous outflow obstruction from other causes of perivenular fibrosis are described.