OBJECT The object of this study was to assess the long-term outcome and quality of life of patients who have survived with severe disability following decompressive craniectomy for severe traumatic brain injury (TBI). METHODS The authors assessed outcome beyond 3 years among a cohort of 39 patients who had been adjudged either severely disabled or in vegetative state 18 months after decompressive craniectomy for TBI. Assessments performed included the Extended Glasgow Outcome Scale, modified Barthel Index (mBI), Zarit Burden Interview, and 36-Item Short-Form Health Survey (SF-36). The issue of retrospective consent for surgery was also assessed. RESULTS Of the 39 eligible patients, 7 died, 12 were lost to follow-up, and 20 patients or their next of kin consented to participate in the study. Among those 20 patients, 5 in a vegetative state at 18 months remained so beyond 3 years, and the other 15 patients remained severely disabled after a median follow-up of 5 years. The patients' average daily activity per the mBI (Pearson correlation coefficient [r] = -0.661, p = 0.01) and SF-36 physical score (r = -0.543, p = 0.037) were inversely correlated with the severity of TBI. However, the SF-36 mental scores of the patients were reasonably high (median 46, interquartile range 37-52). The majority of patients and their next of kin believed that they would have provided consent for surgical decompression even if they had known the eventual outcome. CONCLUSIONS Substantial physical recovery beyond 18 months after decompressive craniectomy for severe TBI was not observed; however, many patients appeared to have recalibrated their expectations regarding what they believed to be an acceptable quality of life.