This article reviews 4 categories of hypertensive disorders of pregnancy: chronic hypertension, gestational hypertension, preeclampsia, and preeclampsia superimposed on chronic hypertension. It focuses on the diagnosis and management of preeclampsia with emphasis on the pharmacologic management of blood pressure during pregnancy. Preeclampsia is one of the most common medical disorders affecting pregnancy, with significant maternal and fetal morbidity and mortality. The most serious maternal complications of preeclampsia include intracerebral hemorrhage, eclampsia, and renal failure, as well as hemolysis, elevated liver enzymes, and low platelets (HELLP) syndrome and posterior reversible encephalopathy syndrome (PRES).