Plasma tocopherol levels of less than 0.8 microgram/g lipid were considered indicative of a vitamin E-deficient status. Based on this criterion, 10 out of 13 sickle cell anemia patients who were not in crisis, were considered deficient in vitamin E as compared to none of 24 normal control subjects. Sickle cell anemia patients treated with 150 IU vitamin E (dl-alpha-tocopheryl acetate) three times a day for 1 to 2 months had plasma tocopherol levels similar to control subjects. The possible role of vitamin E status on the manifestation of sickle cell anemia is discussed. The present study confirmed the vitamin E-deficient status of subjects with beta-thalassemia. Six of seven patients with beta-thalassemia had tocopherol levels of less than 0.8 mg/g lipid.