In homozygous beta-thalassemia low serum level of alpha-tocopherol have been found. The administration of high doses of the vitamin increased the serum level, decreased lipid peroxidation and, in some case, prolonged red blood cell survival; no significant change in transfusion requirement was obtained. Only few data are available about the vitamin E in heterozygous beta-thalassemia. We have studied 131 patients aged 1 to 72 years with thalassemic trait and 218 age-matched controls. Serum level of alpha-tocopherol was statistically lower in the former. We have studied the effect of vitamin E on 10 patients. In each subject the subsequent parameters were determined before and after a three month treatment (vitamin E 400-600 mg/day) glutathione peroxidase, pyruvate kinase and creatine in erythrocytes serum vitamin E and red blood cell count. Hematological values were unchanged in all patients. In half of them biochemical parameters showed reduction of lipid peroxidation and increased erythrocyte survival.