In 1975 and 1976 190 head injury patients died after admission to 19 general hospitals in Mersey Region or after transfer to the regional department of neurosciences. Their hospital case-notes were examined. Avoidable factors definitely contributing to death were identified in 58 (30%), and those possibly contributing to death in another 45 (24%). Of the avoidable factors 38% occurred in patients who "talked and died" and 77% in patients with intracranial haematomas. The most common avoidable factors were failure to recognise the development of a haematoma, respiratory difficulty leading to hypoxia, hypotension, and convulsions. The following recommendations are made: hospital case-notes of all head injury deaths should be assessed by a panel of senior consultants; all patients unconscious for 4 h in primary surgical wards in general hospitals should be transferred to the regional department of neurosciences; and fewer patients with minor head injuries should be admitted for observation.