A 62-yr-old woman, admitted to Mitsui Memorial Hospital with complaints of jaundice, general malaise and anorexia, was diagnosed as acute hepatitis A by positive IgM anti-HA. On the 13th hospital day, indirect hyperbilirubinemia (total bilirubin 57 mg/dl, indirect bilirubin 38.5 mg/dl) and splenomegaly were noted. Hemoglobin concentration decreased to 8.4 g/dl and reticulocytes increased to 6%. Bone marrow showed hyperplastic marrow with erythroid hyperplasia. Coombs test was negative. After administration of prednisolone 40 mg daily for 30 days, hemoglobin concentration increased to 11.9 g/dl and total bilirubin was decreased to 0.4 mg/dl. The liver biopsy specimen obtained on the 62nd day, revealed recovery stage of acute hepatitis. Jaundice with increased indirect bilirubin, anemia with reticulocytosis, elevated plasma hemoglobin concentration and predominance of LDH1 were indicative of hemolysis. The enzyme activities in the red blood cells, which were taken 1 year after the onset, were within normal limits. Scanning electron microscopy of the red cells showed no significant abnormalities in their shape and the nature of the surface.