Hepatic parenchymal changes associated with Budd-Chiari syndrome (BCS) have been tentatively explained by combined arterial and portal perfusion disturbances in addition to the complete occlusion of hepatic veins. The aim of this study was to correlate pretransplant course and vascular imaging with pathologic findings in livers explanted for BCS. Seventeen consecutive white patients who underwent transplantation for severe classic BCS were retrospectively analyzed. Pretransplant course was 1 year or less in 8 patients and more than 1 year in 9 patients. Thrombophilia was found in 16 patients (94%). Imaging showed decreased portal perfusion in 16 patients (94%) and increased arterial perfusion in 9 patients. Histology showed obstructive portal venopathy and nodular regenerative hyperplasia (NRH) aspects in all cases, large regenerative nodules resembling focal nodular hyperplasia (FNH) in 9 cases, and cirrhosis in 2 cases. Patients with increased arterial inflow had large regenerative nodules and a protracted pretransplant course. Patients with acute thrombi in portal veins had parenchymal infarcts (2 cases) and a short pretransplant course. In conclusion, patients with severe BCS have a constant impaired perfusion inflow unrelated to progression of cirrhosis but related to the outcome. An early decrease in portal perfusion is observed in the short term and is responsible for NRH or infarcts if complicated with large thrombi. An increase in arterial perfusion compensates impaired portal flow in chronic BCS. Arterial hyperemia contributes to the development of large regenerative nodules that are FNH-like. This pathologic situation offers an interesting vascular model to further understand the parenchymal response to changes in hepatic blood flow.