The authors have studied the findings of radionuclear scanning inferior vena cavography and ultrasonography in 2 cases of Budd-Chiari Sydrome experienced recently. Radionuclear scanning of the liver revealed diffuse inhomogeneous uptake throughout enlarged liver without cold defects. Slightly increased activity in the central portion of liver in case I and markedly increased activity in the caudate lobe in case II were observed. In inferior vena cavography, the dilated hepatic veins forming intrahepatic collaterals were seen in enlarged caudate lobe. Marked stenosis of I.V.C. at the level of confluence to right atrium, intraluminal thrombosis of I.V.C., partial obstruction of hepatic veins by thrombi at the confluent portion and systemic collaterals were noted in case I. In case II, abrupt conical obstruction of I.V.C. at the orgin of hepatic segment, which is consistent with membrance or web, was seen. Prominent systemic collaterals were developed through the serpinginous mar edly dilated azygos and hemiazygos veins, and splenorenal shunt. In ultrasonography, diffuse narrowing and obstruction of hepatic veins at the confluent level by echogenic nodules were seen in 2 cases. Prominent intrahepatic venous collaterals were observed in case II.