This chapter addresses matters of general concern regarding the use of cellular blood products in acute care settings and focuses more specifically on the goal of transfusion support of hemostasis. Transfusion in surgery, trauma, and intensive care requires vigilant attention to the unique physiological status of pediatric patients, particularly in the neonatal period. Transfusion is a major component of pediatric patient care in surgery, trauma, and the intensive care unit (ICU). Although the medical needs of patients may be acute, the careful and judicious use of blood products is very important. Widely observed guidelines for transfusion triggers in pediatric populations have not been established. One of the most controversial issues in pediatric transfusion is the appropriate use of small volume transfusions of RBCs to replace blood lost from laboratory testing or for other insidious causes of anemia. Cryoprecipitate and fresh frozen plasma (FFP) remain central components in the treatment and resuscitation of acutely bleeding pediatric patients. However, the appropriate use of these products must also consider a potential role of pharmaceutical hemostatic agents.