Pulmonary hypertension in preterm infants is defined by the same guidelines used for adults and children: mean pulmonary arterial pressure =20 mm Hg, pulmonary capillary wedge pressure <15 mm Hg, and indexed pulmonary vascular resistance >3 Wood units/m2. Bronchopulmonary dysplasia, the major cause of chronic lung disease in preterm infants, is defined as the need for oxygen at 36 weeks postconceptual age in infants born at or before 32 weeks’ gestation. The disruption of growth and function of the pulmonary vasculature observed with bronchopulmonary dysplasia contributes to the development of pulmonary hypertension. Abnormal pulmonary vasculature develops increased pulmonary vascular resistance and mean pulmonary artery pressures. As many of 20%–40% of patients with bronchopulmonary dysplasia have persistent pulmonary hypertension and the combination is accompanied by significant morbidity and mortality. This chapter details the assessment and perioperative considerations involved in caring for a preterm infant with these conditions undergoing multiple surgical procedures.