Aim. The pertinence of the study is related to a large prevalence of dysfunction of the placenta in pregnant women suffering from anemia. To evaluate the immunohistochemical expression characteristics of endothelial NO-synthase (eNOS) in the placenta during its dysfunction in women against the background of anemia 30 samples of placental tissue were studied with the use of immunohistochemical and micrometer methods.Mеthods and results. It was found that the expression of eNOS in patients with iron deficiency anemia in the cytoplasm of syncytium of villi and fetal capillary endothelium as well as decidual vessels decreases, with the most pronounced changes in the expression of eNOS observed in the presence of the combination of placental dysfunction and iron deficiency anemia in the form of paradoxical increase in expression.Conclusion. This indicates the necessity for correction of endothelial function in women with anemia during pregnancy.