Hepatic vena cava syndrome (HVCS) also known as membranous obstruction of inferior vena cava reported mainly from Asia and Africa is an important cause of hepatic venous outflow obstruction (HVOO) that is complicated by high incidence of liver cirrhosis (LC) and moderate to high incidence of hepatocellular carcinoma (HCC). In the past the disease was considered congenital and was included under Budd-Chiari syndrome (BCS). HVCS is a chronic disease common in developing countries, the onset of which is related to poor hygienic living condition. The initial lesion in the disease is a bacterial infection induced localized thrombophlebitis in hepatic portion of inferior vena cava at the site where hepatic veins open which on resolution transforms into stenosis, membrane or thick obstruction, and is followed by development of cavo-caval collateral anastomosis. The disease is characterized by long asymptomatic period and recurrent acute exacerbations (AE) precipitated by clinical or subclinical bacterial infection. AE is managed with prolonged oral antibiotic. Development of LC and HCC in HVCS is related to the severity and frequency of AEs and not to the duration of the disease or the type or severity of the caval obstruction. HVOO that develops during severe acute stage or AE is a pre-cirrhotic condition. Primary BCS on the other hand is a rare disease related to prothrombotic disorders reported mainly among Caucasians that clinically manifest as acute, subacute disease or as fulminant hepatic failure; and is managed with life-long anticoagulation, porto-systemic shunt/endovascular angioplasty and stent or liver transplantation. As epidemiology, etiology and natural history of HVCS are different from classical BCS, it is here, recognized as a separate disease entity, a third primary cause of HVOO after sinusoidal obstruction syndrome and BCS. Understanding of the natural history has made early diagnosis of HVCS possible. This paper describes epidemiology, natural history and diagnosis of HVCS and discusses the pathogenesis of LC in the disease and mentions distinctive clinical features of HVCS related LC.