Post-traumatic epilepsy is a well-known complication of head injury (TCE). There is extensive bibliography on the subject which contains contradictory data and unanswered questions. In this paper, we review and update the literature emphasizing particularly current definitions, incidence, risk factors and evaluation of prophylactic treatment in relation to the physio-pathology. We give data of a retrospective study of the cases observed during the past 15 years in our unit, analyzing the factors which may help to predict the evolution of these crises. There is a relationship between the incidence of post-traumatic epilepsy and the severity of injury. One of the main risk factors is the presence of focal lesions, particularly haemorrhagic lesions. Prophyllactic treatment with anti-epileptic drugs is only effective during the first week in the group at risk of developing early crises. It has not been shown to be of use in preventing post-traumatic epilepsy. Other treatments, such as antioxidants, calcium antagonist and glutamate inhibitors are still only at an experimental stage.