The paper deals with the supremely important and intractable problem that is to manage pregnant women with preeclampsia. Today’s universally accepted theories of the pathogenesis of preeclampsia, such as the role of inadequate gestational transformations of uterine vessels in the uteroplacental unit, placental ischemia; maternal immunological intolerance to the semiallogeneic fetus; vascular endothelial lining damage; and the importance of fetal genetic factors, are considered in the context of the propositions of evidence-based world medicine and the WHO guidelines. The mechanisms involved in the development of vascular and blood coagulation disorders and severe kidney, liver, and brain injuries are analyzed. Attention is drawn to the already solved problems of clinical, laboratory, and instrumental diagnosis of preeclampsia. The WHO guidelines-based treatment practice is presented. At the same time, the audit of maternal deaths in Russia in 2013 has shown that the proportion of severe forms of gestosis does not decline; there is a preponderance of preventable and apparently preventable maternal mortality cases that suggest the necessity of improving diagnosis and medical care in preeclampsia.