OBJECTIVE: To quantify the occurrence of high intracranial pressure (HICP) refractory to conventional medical therapy after traumatic brain injury (TBI) and to describe the use of more aggressive therapies (profound hyperventilation, barbiturates, decompressive craniectomy). DESIGN: Prospective study of 407 consecutive TBI patients SETTING: Three neurosurgical intensive care units (ICU). MEASUREMENTS AND RESULTS: Intracranial pressure (ICP) was studied during the first week after TBI; 153 patients had at least 1 day of ICP>20 mmHg. Early surgery was necessary for 221 cases, and standard medical therapy [sedation, mannitol, cerebrospinal fluid (CSF) withdrawal, PaCO2 30-35 mmHg] was used in 135 patients. Reinforced treatment (PaCO2 25-29 mmHg, induced arterial hypertension, muscle relaxants) was used in 179 cases (44%), and second-tier therapies in 80 (20%). Surgical decompression and/or barbiturates were used in 28 of 407 cases (7%). Six-month outcome was recorded in 367 cases using the Glasgow outcome scale (GOS). The outcome was favorable (good recovery or moderate disability) in 195 cases (53%) and unfavorable (all the other categories) in 172 (47%). HICP was associated with worse outcome. Outcome for cases who had received second-tier therapies was significantly worse (43% favorable at 6 months, p=0.03). CONCLUSIONS: HICP is frequent and is associated with worse outcome. ICP was controlled by early surgery and first-tier therapies in the majority of cases. Profound hyperventilation, surgical decompression and barbiturates were used in various combinations in a minority of cases. The indications for surgical decompression and/or barbiturates seem restricted to less than 10% of severe TBI.