Red blood cells in iron deficiency anemia (IDA) have a decreased activity of essential antioxidant enzymes. The present study examined the effect of in vitro exposure to oxidative agents in IDA cells and their recovery capacity. Red cells of 26 IDA patients and 10 healthy subjects were examined. Cells of IDA patients had higher levels of reduced glutathione (GSH), and normal methemoglobin and malonyldialdehyde (MDA) levels. Exposure to butyl hydro-peroxide revealed a dose-dependent sensitivity in IDA cells, with extensive GSH depletion and increased MDA levels. These changes were partially reversible by incubation with dithiothreitol. Exposure to phenazine methosulfate, to produce intracellular superoxide ions, resulted in moderate GSH depletion and methemoglobin production. IDA cells were more sensitive than control cells to high concentrations of this substance. This effect was further augmented by preincubation with a superoxide dismutase inhibitor. Our data demonstrate that IDA cells are more susceptible to oxidation but have good capacity for recovery.