Thirty-four children, aged 1-14 years, with severe chronic liver disease were studied to determine the incidence of chronic hemolytic anemia and the mechanism underlying it. Sixteen children were grouped as vitamin E-deficient patients (Group I, serum vitamin E level below 5.0 micrograms/ml) and compared with 18 vitamin E-sufficient children (Group II) and 20 healthy controls. Group I patients had a significantly lower hemoglobin level (11.6 +/- 0.4 g/dl) when compared with Group II (12.9 +/- 0.4 g/dl, less than 0.05), their RBC's were less resistant to H2O2-induced hemolysis (53.1 +/- 8.0% in Group I, vs. 1.07 +/- 0.23% in Group II), and the average hemolysis correlated with serum vitamin E levels. H2O2-induced hemolysis reverted to normal in five patients after vitamin E therapy. With respect to controls, cirrhotic children in both groups showed a slight increase in total RBC membrane lipids, but no difference in either phospholipid content or in cholesterol/phospholipid molar ratio that could have changed RBC membrane properties and sensitivity to lysis. In our experience, vitamin E-deficient cirrhotics have a slight degree of chronic hemolytic anemia and their RBC's are much more sensitive to H2O2 lysis, although this abnormal lysis susceptibility does not seem apparently related to membrane peroxidation.