The ultimate neurologic outcome following severe head trauma depends on the extent of primary brain insult sustained at the time of the trauma itself, and the subsequent neurochemical and neurophysiologic pathologic changes occurring as a result of the injury. Although there are currently no specific therapies that have proven to be consistently effective in reversing the devastating consequences of primary brain insult, the reduction or prevention of secondary brain insult is possible. The emergent resuscitation and care of the severely head injured patient can therefore impact the patient's final neurologic outcome. As new data are accumulated, traditional and new therapies for severe head injury have come under scrutiny. While no absolute standards have been advanced, guidelines have been established that can help direct the acute stabilization of severely head injured patients.