Hemodynamic monitoring is the monitoring of the changes in cardiovascular physiology as they occur. It includes both basic cardiovascular system observations and the so-called advanced parameters (such as NIRS, non-invasive continuous cardiac output monitoring, and functional echocardiography), some of which are measured invasively. Cardiovascular dysfunction is one of the commonest organ system failures that occur in critically ill children, whether as the primary derangement such with severe sepsis, or as a secondary feature of other organ system dysfunction. Specific relevant chapters on other organ systems feature throughout this book, e.g. congenital heart disease and surgical chapters. In this chapter, we focus on generic basic and advanced hemodynamic assessment and management during resuscitation, stabilization, and ongoing critical care.