In the last several years, there have been numerous advancements in the field of pulmonary hypertension as a whole, but there have been few changes in the management of children with pulmonary hypertension after cardiac surgery. Patients at particular risk for postoperative pulmonary hypertension can be identified preoperatively based on their cardiac disease and can be grouped into four broad categories based on the mechanisms responsible for pulmonary hypertension: 1) increased pulmonary vascular resistance; 2) increased pulmonary blood flow with normal pulmonary vascular resistance; 3) a combination of increased pulmonary vascular resistance and increased blood flow; and 4) increased pulmonary venous pressure. In this review of the immediate postoperative management of pulmonary hypertension, various strategies are discussed including medical therapies, monitoring, ventilatory strategies, and weaning from these supports. With early recognition of patients at particular risk for severe pulmonary hypertension, management strategies can be directed at preventing or minimizing hemodynamic instability and thereby prevent the development of ventricular dysfunction and a low output state.