Context: Chronic traumatic encephalopathy (CTE) is a rare progressive neurologic disorder that can manifest as a combination of cognitive, mood and behavioral, and neurologic symptoms. Despite clinically apparent symptoms, there is no imaging or other diagnostic test that can confirm diagnosis in living subjects. Diagnosis can only be confirmed postmortem by specific histopathologic features within the brain tissue identified on autopsy. CTE represents a unique tauopathy that is distinct from other neurodegenerative diseases. Evidence Acquisition: PubMed was searched from 1990 to 2013 for sport concussion and chronic traumatic encephalopathy. Articles were also identified from bibliographies of recent reviews and consensus statements. Study Design: Clinical review. Level of Evidence: Level 5. Results: Although CTE is postulated to occur as a result of repetitive mild traumatic brain injury, the specific etiology and risk factors have not yet been elucidated, and postmortem diagnosis makes causality difficult to determine. Conclusion: When counseling athletes and families about the potential association of recurrent concussions and the development of CTE, discussion of proper management of concussion is cornerstone. Unfortunately, to date, there is no equipment that can prevent concussions; however, rule changes and legislation may decrease the risk. It is imperative that return to play is medically supervised by a provider trained in the management of concussion and begins only once symptoms have resolved. In addition, athletes with permanent symptoms should be retired from contact sport.