The mature human erythrocyte, when submitted to oxidative stress, can demonstrate depletion of reduced glutathione, oxidation of the hemoglobin molecule and aggregation of complexes of iron close to the membrane. These can produce abnormalities in the erythrocyte membrane and hemolysis. The aim of this work was to study the antioxidative action of vitamin C (vit. C), deferroxamine (DFO) and the flavonoids quercetin and rutin in normal human erythrocytes, submitted to in vitro oxidative stress induced by tert-butylhydroperoxide ((t)BHP). Venous blood was collected in citrate-phosphate-dextrose (CPD) solution, as anticoagulant, from healthy adult individuals after informed consent. The erythrocytes were resuspended in PBS to obtain 35% globular volume, and then submitted to the oxidative action of (t)BHP for up to 30 min, with or without previous incubation for 60 min with vit. C, DFO, quercetin and rutin. Decrease in the GSH concentration, G6-PD and GR activities, and increase in the methemoglobin and Heinz bodies (HB) formation, occurred with the increase in (t)BHP concentration. (t)BHP did not effect on the membrane proteins detected by SDS-PAGE. Quercetin, partially prevented the GSH decrease and the formation of HB, but did not prevent MetHb formation from oxidative damage by (t)BHP. Rutin, after (t)BHP induction, prevented the GSH decrease and the formation of HB. Vit. C, had no influence on the depletion of GSH, inhibited partially the metHb formation, and it protected GR, but not G6-PD from oxidative damage by (t)BHP. DFO partially inhibited the metHb formation and GSH decrease, but it did not protect GR and G6-PD from oxidative damage by (t)BHP. The results obtained suggest that vit. C, DFO and the flavonoids quercetin and rutin contribute to the decrease in the oxidative stress caused by (t)BHP.