Drainage of cerebrospinal fluid by means of external lumbar drainage (ELD) is controversial in the adult population with traumatic brain injury. We report our experience with ELD in the treatment of post-traumatic high intracranial pressure (ICP) and the results of the long-term follow-up in these patients. We undertook clinical evaluation of 30 patients with traumatic brain injury and high ICP treated with second-tier measures or with first-tier measures if second-tier measures were contraindicated. The study involved a retrospective review of collected data. Outcome at intensive care unit discharge and three to five years after injury were evaluated with the Glasgow Outcome Scale. The mean age of patients was 34.9 +/- 12.5 years and 25 (83%) were male. The median (interquartile range) Glasgow Coma score was 8 (7 to 10). ICP before and one hour after ELD placement was 33.7 +/- 9.0 and 12.5 +/- 4.8 mmHg respectively, a decrease in 21.2 +/- 8.3 mmHg (P < 0.0001). ELD was placed after a mean of 8.6 +/- 3.9 days. Cerebrospinal fluid drainage was maintained for a mean of 6.6 +/- 3.5 days. Four patients (13%) required ELD replacement and one patient developed a cerebrospinal fluid infection (3%). No pupillary changes were noted within 48 hours of ELD placement. Long-term outcome was favourable (good recovery or moderate disability) in 62% of the patients studied. The use of ELD resulted in a marked decrease in ICP These patients presented a good outcome in 62% of the cases in the long-term evaluation. Few complications related with ELD use were noted.