The purpose of this study was to evaluate the influence of additional, extracranial injuries and subsequent neurological complications in the intensive care unit on the functional outcome after head injury with extradural haematoma. The retrospective analysis included 139 adult patients with acute extradural haematomas admitted to the intensive care unit. Fifty-seven patients (41 per cent) were multiply injured (Injury Severity Score (ISS) = 36.5), and 82 (59 per cent) had a single head injury (ISS = 24.9). Fifty-four patients (39 per cent) developed neurological complications such as intracranial pressure (ICP) increase alone (N = 16), intracranial bleeding, ischaemic brain lesions or epileptic seizures with an associated ICP increase (N = 24) or without (N = 14). Overall, 77 per cent of the patients had a functional outcome (Glasgow outcome score 4 or 5); 46 per cent had a good recovery, 31 per cent were moderately disabled, 10 per cent were severely disabled, 4 per cent were persistently vegetative, and 9 per cent died. Differences were found between (1) patients with and without complications, (2) patients with extradural haematomas and patients with additional intracranial lesions, and (3) patients with a 'severe' Glasgow Coma Score (GCS) of 3-8 and patients with a GCS of 9-15. The presence of additional intracerebral injuries, and not extracerebral injuries, as well as the management of elevated ICP determines the final outcome in patients with extradural haematomas.