Traumatic brain injury (TBI) has been recognized as a risk factor for developing dementia. Currently, around 69 million people worldwide suffer from TBI each year, while the overall incidence of TBI among Chinese residents is on a rapid rise. Such a large population of TBI patients may lead to a future surge in the number of dementia patients, bringing heavy burdens on families and societies. However, it seems to be suggested by numerous studies that not all TBI patients are associated with an increased risk of dementia. Dementia can result in disability as well as interfere with caregivers ′ normal lives. Therefore, it will be significant to clarify the relationship between TBI and dementia as well as explain the process of onset and development of post-TBI dementia. In this study, the authors summarize post-TBI dementia from aspects of influencing factors and pathogenic mechanisms, so as to provide relevant references for related studies, therapy, and prophylaxis of post-TBI dementia.