This was a prospective, observational study of children aged 3 to 15 years admitted to hospital with head injury (HI). Demographic data and information on the nature of the HI, and history of premorbid headache were collected. A structured telephone questionnaire was used to interview parents and children 2 months after injury and at 4-monthly intervals for up to 3 years, if headache was reported. One hundred and ninety children were admitted with HI. Data were available on 117 children (81 males, 36 females; mean age 8y 5mo [SD 3y 1mo]). HI was minor in 93 patients and significant in the rest. Minor HI was defined as a closed injury, no loss of consciousness, and a Glasgow Coma Score (GCS) of 13 to 15. Significant HI was associated with loss of consciousness for >30 minutes, GCS of <13, and post-traumatic amnesia for >48 hours. Eight children (five males, three females; mean age 10y 7mo [SD 2y]) reported chronic post-traumatic headache (CPTH). Five children had episodic tension-type headache and three had migraine with or without aura. Headache resolved over 3 to 27 months in all except one child who was lost to follow-up. Premorbid headache in three children transformed in frequency and type following HI. These patients were excluded from the study. CPTH is common after minor and significant HI. It has the clinical features of tension-type headache and migraine and has a good prognosis.