It is difficult to accurately determine the number of people affected annually by the devastating effects of traumatic brain injury. It is clear, however, that the impact of traumatic brain injury exceeds the financial cost of acute health care. The long-term outcome of patients with traumatic brain injury has been targeted specifically for improvement during this decade. The initial brain injury--known as the primary injury--may occur in one area of the brain (focal injury) or may affect the entire brain (diffuse injury). The outcome depends on many factors, including the severity of the brain injury and the effectiveness of the interventions received. Accurate assessment of the scope of the problem would be improved by the development of a national database and the standardization of assessment practices. Critical care nurses can contribute skill and knowledge in the care of patients with traumatic brain injury and in efforts to prevent the accidents and violence that cause traumatic brain injury.