Background: Preeclampsia-eclampsia and acute renal failure in peripartum women can be the cause of mortality and morbidity. There are many different reports about oxidative-antioxidative systems in preeclampsia-eclampsia. Until now, products of activated oxidative-antioxidative systems were not evaluated in peripartum women with acute renal failure. In this study, our aim was to evaluate the oxidative-antioxidative systems in peripartum women with acute renal failure and/or preeclampsia-eclampsia. Methods: The study groups consisted of 17 peripartum women (first week of delivery) with acute renal failure (G I), 11 preeclamptic (G II), 11 healthy pregnancy ( greater than or equal to 30 weeks of pregnancy) (G III), and 11 healthy women (G IV) aged between 18-38 years. Superoxide dismutase (SOD), glutathione peroxidase (GSHPx) in erythrocytes, and plasma malondialdehyde (MDA) levels were measured in all groups. SOD, GSHPx, and MDA levels were also measured at the onset of acute renal failure (G IA), regression of renal dysfunction (G IB) and recovery of renal functions (G IC). Results: MDA levels were 11.95 +/- 4.25, 9.22 +/- 3.62, 5.10 +/- 3.65, 3.40 +/- 1.27, 4.91 +/- 2.06, 4.24 +/- 1.67 mmol/mL in G IA, G IB, G IC, G II, G III, and G IV, respectively. SOD activity in erythrocyte were 3269.23 +/- 1437.83, 2641.35 +/- 1411.13, 2056.35 +/- 1143.11, 924 +/- 160.04, 1057.91 +/- 257.03, 861.63 +/- 243.28 Ug/Hb in G IA, G IB, G IC, G II , G III, and G IV, respectively. GSHPx activity in erythrocyte was 70.17 +/- 23.52, 58.27 +/- 23.75, 45.44 +/- 17.60, 24.48 +/- 6.77,26.28 +/- 7.27,32.95 +/- 8.24 Ug/Hb in G IA, G IB, G IC, G II, G III, and G IV, respectively. MDA levels and activities of SOD, GSHPx in erythrocytes were highest in GIA The values of MDA, SOD, and GSH-Px in G IA, G IB, and G IC were significantly different from each other and decreased while regaining of renal functions. Preeclampsia-eclampsia or normal pregnancy did not cause elevation of plasma MDA levels and GSHPx, SOD in erythrocyte. Conclusion: Although SOD and GSHPx in erythrocytes and plasma MDA level were found to be similar in healthy women, pregnant women, and preeclamptic women; SOD, GSHPx, and MDA increased at the beginning and decreased during recovery of renal functions in peripartum women with acute renal failure.