OBJECT: It is generally believed that the outcome of traumatic brain injury is not improved by decompressive craniectomy in patients older than 30-50 years. A literature search was performed to assess the level of evidence with respect to the effect of age on outcome in these cases. METHODS: References were identified by PubMed searches of journal articles published between 1995 and December 2008. The inclusion criteria were as follows: 1) clinical series including adults; and 2) focus on age as a prognostic factor. Technical notes and laboratory investigations were excluded. RESULTS: Fourteen English-language articles were finally selected. In 5 of the 14 studies, the authors performed no statistical analysis. In 6 studies they concluded that age was not significantly related to outcome (with 1 of these studies showing a correlation between age and outcome only after 65 years). Three studies showed a correlation between age and outcome. CONCLUSIONS: With respect to age and effectiveness of decompressive craniectomy, there are no robust data to establish any degree of core evidence and the referred age thresholds are arbitrary.