Chronic traumatic encephalopathy (CTE) is a progressive neurodegenerative disease. It belongs to a group of diseases called tauopathies, for which abnormal tau protein aggregation in the brain is the hallmark feature. First case reports and descriptions of CTE were published as early as the first half of the 20th century. Today it is recognized that despite sharing some of the clinical features of other neurodegenerative diseases such as Alzheimer’s disease, frontotemporal dementia, amyotrophic lateral sclerosis, and Parkinson’s disease, CTE is a neuropathologically distinct entity. The etiology of CTE is associated with repetitive traumatic brain injury, specifically concussions and subconcussive brain trauma. It is therefore common in athletes, military personnel and other victims of repetitive brain trauma. The clinical presentation of CTE includes memory loss and other types of cognitive impairment, aggressive behaviour, Parkinsonism, gait and speech problems, depression with suicidal tendencies, and finally dementia.