Background: The pathogenesis theories of preeclampsia include inappropriate trophoblast invasion and incomplete remodeling of spiral uterine arteries. This is followed by a reduced utero-placental perfusion; ischemia is the cause of oxidative stress activation. The imbalance between the oxidant and antioxidant components in favor of pro-oxidation, induce endothelium activation and / or dysfunction with the occurrence of clinical and laboratory manifestations. Material and methods: It was proposed a comparative prospective study including 105 pregnant women with preeclampsia in comparison with 367 pregnancies without preeclampsia. Pro-oxidant and antioxidant status and its correlation with systolic blood pressure values and classical laboratory marchers were analyzed. Results: In preeclampsia there is an excess accumulation of pro-oxidants comparing to control group p<0.001. Malondialdehyde and Advanced Oxidation Protein Products are most implicated in hypertensive syndrome r 0.7, p<0.001. Inflammatory diseases of uro-excretory tract accompanying preeclampsia, demonstrate excess accumulation of Advanced Oxidation Protein Products and AGE verprelizine-like and AGE pentozidine-like r 0.7, p<0.001. Modified ischemic albumin did not get the modified value in the research group. Conclusions: Excess accumulation of pro-oxidants in preeclampsia plays an important role in pathogenesis pathway, clinical and laboratory manifestation of preeclampsia