A trauma center is a hospital equipped to perform as a casualty receiving station for the emergency medical services by providing the best possible medical care for traumatic injuries on a 24 hour, 7 days per week, 365 days per year basis. The trauma center is so-named because a trauma patient often requires immediate and complex surgery in order to survive. One reason for the establishment of trauma centers is the recognition in emergency medicine that trauma patients often needed immediate surgery, when most emergency rooms lacked the staff required to perform the surgery immediately.

In order to qualify as a trauma center, a hospital must have a number of complex capabilities including a well-stocked emergency room, a strong emergency medicine department supervised by a highly qualified specialist, a trauma service led by a team of trauma surgeons and supported by advanced diagnostic equipment immediately available to the trauma team such as a computed tomography (CT) scanner, and surgical specialists such as neurosurgeons and orthopedic surgeons on duty. A trauma center must also have a helipad for receiving patients by MEDEVAC and well-developed contingency plans for disasters.

Emergency medical technicians, when deciding which hospital to take a patient to, must consider the capabilities of the receiving facility. There is little point to taking a patient to a local community hospital if the patient's condition requires advanced medical care unavailable at that facility.

One of the limitations on a trauma center's operation is sufficient supplies of blood for use in blood transfusions. Other limitations include the number of patients being treated and whether or not a disaster is taking place. A trauma center, like other hospitals may be forced to close its doors to incoming patients if overwhelmed by patients. This is a form of triage; in this case patients are taken to other area and regional facilities which still have the capability of helping severely injured patients.

The operation of a trauma center is extremely expensive. Some areas are under-served by trauma centers because of this expense. Persons injured in remote areas and brought to a trauma center by helicopter often receive faster and better care than a person injured in a city and taken to a normal hospital by ground ambulance.

In the United States, trauma centers are ranked into four categories, ranging from the lowest level of care in Level IV facilities up to comprehensive service in Level I centers. Some centers specialize in adult or pediatric care.