Aims and Objectives: Preeclampsia and eclampsia are pregnancy complications with serious consequences for mother and infant. Uncontrolled lipid peroxidation may play an important role in the pathophysiology of preeclampsia and eclampsia by causing vascular endothelial cell dysfunction. Antioxidants serve to control lipid peroxidation. We attempted to ascertain whether antioxidant protective mechanisms are diminished in women with preeclampsia and eclampsia. Materials and Methods: Lipid peroxidation and antioxidant markers were assayed in 25 healthy non-pregnant women as a control group, 25 third trimester normal pregnant women, 25 preeclamptic and 25 eclamptic patients of the same trimester by standard spectrophotometer methods. Results: In preeclampsia and eclampsia malondialdehyde, a product of lipid peroxidation, was significantly increased while enzymatic antioxidants like superoxide dismutase, glutathione peroxidase, glutathione reductase and catalase were significantly reduced as compared to normal pregnant women and non-pregnant controls. Conclusion: Lipid peroxidation is an important factor in the pathogenesis of preeclampsia and eclampsia. The decrease in antioxidants is probably due to a compensatory nature responding to the increased lipid peroxide load in preeclamptic and eclamptic patients and may indicate the severity of the disease.