Mild traumatic brain injury (mTBI) is becoming topical with potential association with post-traumatic stress disorder (PTSD) and dementia and questions are being raised for the Defence Forces. Traumatic brain injury results from head trauma causing altered consciousness or post-trauma amnesia and may be categorised as mild, moderate or severe. It has been recognised since World War I and has re-emerged as a source of concern in sports men and women with potential litigation becoming a reality. Its association with PTSD, cognitive dysfunction, depression and other neurological symptoms is being increasingly recognised with new imaging techniques demonstrating pathology not identified in standard CT and MRI. In June 2012, a U.S. class action for 2.500 football players was initiated and has the potential to be the forerunner of similar actions within the Defence Forces.