In a 54-year-old woman with oesophageal varices there were the unusual morphological findings of portal-vein aneurysm and irregular hepatic fibrosis. The patient had been treated for 8 years for polycythaemia vera with transition into myelofibrosis. Histologically the hepatic tissue showed occlusion of intrahepatic portal-vein branches by organised thrombi, as well as angiomatous vessels in the sclerosed portal areas. the increased pressure as well as medial atrophy with portal-vein sclerosis were the cause of the portal-vein aneurysm. Portal hypertension may have been the result of intrahepatic vascular obstruction and of the increased flow through the enlarged spleen. It is suggested that interaction of several factors, related to the basic disease of myelofibrosis led to these complex anomalies of the liver and portal vascular system.