ALTHOUGH the importance of oxygen in maintaining functional and morphological integrity of the liver is well established in experimental animals, little is known of the factors which govern hepatic oxygen uptake in man. The present investigation was undertaken to determine further the relationship of availability and utilization of oxygen by the normal and diseased liver.1Observations were made on splanchnic oxygen consumption in health, effects on hepatic oxygen uptake of altering availability or cellular requirements of oxygen, and the value of oxygen inhalation in correcting hepatic oxygen deficits. Material and Methods Studies were conducted on 16 normal subjects, 12 patients with pulmonary disease, and 20 patients with cirrhosis. Each of the subjects received a hematocrit, biochemical liver function tests, a percutaneous liver biopsy, and pulmonary function tests. Under basal conditions, right hepatic vein catheterization was performed,2and hepatic blood flow measured by the Fick principle using a constant