Care of the severely injured trauma patient is a complex, team-driven task. Patients can present to hospitals with little or no warning and require immediate provision of life- and limb-sustaining treatment by a wide array of healthcare professionals. Optimal care depends not only on the medical or surgical aspects but also on the delivery of care within the context of a trauma team. Team leadership, role assignment, communication, and organization have significant bearing on the performance of the team, and ultimately on the care provided to the patient. This chapter reviews the development of institutional trauma teams and explores their structure and organization.