Blood pressure (BP) in neonates depends on a variety of factors, including gestational age, postnatal age and birth weight. The incidence of hypertension in neonates ranges from 0.2 to 3%, and may be higher in premature infants and those who have undergone umbilical arterial catheterization, or who have chronic lung disease. A careful diagnostic evaluation should lead to determination of the underlying cause of hypertension in most infants. Treatment decisions should be tailored to the severity of the hypertension, and may include intravenous and/or oral therapy. Hypertension will resolve in most infants over time, although a small number may have persistent BP elevation throughout childhood. This review will focus on the differential diagnosis of hypertension in the neonate, the optimal diagnostic evaluation, and therapy.