Serial computed tomographic (CT) studies were performed in 48 patients with brain contusion. Traumatic intracerebral haematoma (TIH) had developed within 6 hours in 56% of the cases, within 12 hours in 81% and 100% within 24 hours from the onset. TIH reached its maximal size in 84% of the cases within 12 hours. The incidence of the appearance of TIH from brain contusion was 52%. The performance of frequent CT examination within 24 hours following head injury would help to lower the mortality rate of such trauma.