Iron is important general well being, to prevent or treat anemia, and is a cofactor of many enzymes in the anti-oxidant process. Effect of sodium iron ethylenediaminetetraacetate (NaFeEDTA) and ferrous sulfate on iron bioavailability and oxidative stress in anemic pregnant women was evaluated. A 2-month randomized controlled trial was conducted on 153 anemic pregnant women, with 80 <= Hb <110 g/L. They were randomly allocated to three groups: group C (n=51) was the placebo control group, group I (n=51) was supplemented daily with 60 mg iron as ferrous sulfate, and group IE (n=51) with 60 mg iron as NaFeEDTA. Blood samples were collected before and at the end of the intervention for measurements of hematological indices and oxidative stress parameters. Considerable increases of hematologic indicators were observed: 20.5 and 21.8 g/L for Hb (both p values <0.001); 4.81 and 7.19 μmol/L for plasma iron (both p values <0.001), 2.63 and 8.99 μg /L for ferritin (both p values <0.05) in I and IE groups, respectively, compared with the control group. Glutathione peroxidase (GSH-Px) activities increased by 32.6 and 75.3 IU/ml, and malondialdehyde (MDA) levels decreased by 0.70 and 1.12 μmol/L in I and IE groups, compared with the C group (p values <0.05). Moreover, differences of plasma iron, ferritin and GSH-Px activity were 2.38 μmol/L, 6.36 μg /L and 42.7 IU/ml were also significantly greater in the IE group than in the I group. Moderate iron supplementation may be beneficial to improving iron deficiency and oxidative stress, and NaFeEDTA is better than ferrous sulfate.