The management of the pediatric patient following cardiac surgery is predicated on the clinician having a thorough understanding of a broad fund of knowledge, with an emphasis on pulmonary function, cardiovascular function, and the interaction between these two systems. An appreciation of the patient’s preoperative history and intraoperative course, including a deliberate review of all studies, enables the clinician to synthesize a comprehensive plan that is tailored to the needs of a given patient. Postoperative management begins with the physical examination, a survey of respiratory and hemodynamic parameters, as well as radiographs and basic laboratory studies. Based on the integration of all data, a determination of the severity of illness and an initial management strategy is established. At its core, the assessment should attempt to identify residual cardiac lesions and other potential clinical pitfalls. Monitoring strategies are used to provide acute and accurate surveillance, as it is much more advantageous to manage patients in an anticipatory rather than reactionary fashion. Over time, the clinical course is reassessed, assuring that the patient’s clinical trajectory is proceeding as expected. The goal of this chapter is to provide the underpinnings necessary for completing these tasks.