• Twelve patients with clinical and laboratory evidence of cirrhosis were compared with four healthy men with respect to hematological findings. The laboratory tests included determination of the halflife of the red blood cells by a methd involving the use of sodium radiochromate to label the subject's red blood cells. The red blood cell half-life for the 12 cirrhotic patients ranged from 21 to 37 days. Patients whose red blood cells manifested a shortened half-life were more likely than other patients to have an indirect serum bilirubin level of 1.8 mg. per 100 ml. or above, an elevated mean corpuscular hemoglobin value, and evidence of esophageal varices.