In homozygous sickle cell disease (SCD), decreased serum Vitamin E is present. Excessive transfusions may lead to iron overload. We hypothesised a relationship between the two and found that Vitamin E type antioxidant capacity was significantly lower in 30 SCD patients than in 30 age- and sex-matched controls (P < 0.001). Antioxidant capacity was lower in 10 transfused patients compared with 20 non-transfused patients (P < 0.001). Transfusional iron overload in SCD may increase the potential for oxidative damage, and low antioxidant capacity may compound this effect.