Patients who "talk and deteriorate" are defined as those who utter recognizable words at some time after head injury and then deteriorate to a severe head-injured condition (Glasgow Coma Scale score of 8 or less) within 48 hours of injury. They represent a very small but important subgroup of patients with brain injury. In approximately 75% of these patients, the cause of this deterioration is intracranial hematoma. Despite the fact that talking indicates nonlethal impact brain injury, deterioration is a marker of poor prognosis. Outcome depends on early recognition of deterioration and rapid removal of mass lesions. The challenge for emergency physicians is to distinguish patients at risk for deterioration from the many patients evaluated after head injury.