['To determine the usefulness of S-100β, a marker for central nervous system damage, in the prediction of long-term outcomes after mild traumatic brain injury (MTBI) Hypothesis: Mid- and long-term outcomes of MTBI (i.e. 3, 6 and 12 months post-injury and return-to-work or school (RTWS)) may be predicted based on pre-injury and injury factors as well as S-100β.', 'MTBI subjects without abnormal brain computed tomography requiring intervention, focal neurological deficits, seizures, amnesia\u2009>\u200924 hours and severe or multiple injuries were recruited at a level I trauma centre. Admission S-100β measurements and baseline Concussion Symptom Checklist were obtained. Symptoms and RTWS were re-assessed at follow-up visits (3-10 days and 3, 6 and 12 months). Outcomes included number of symptoms and RTWS at follow-up. Chi-square tests, linear and logistic regression models were used and p\u2009<\u20090.05 was considered statistically significant.', 'One hundred and fifty of 180 study subjects had S-100β results. Eleven per cent were unable to RTWS at 12 months. S-100β levels were not associated with post-concussive symptomatology at follow-up. In addition, no association was found between S-100β levels and RTWS.'] Does s-100β predict outcome after mild traumatic brain injury?