This study of prevalence is based in a population of 34,577 people aged from 15 to 19 resident in the canton of Vaud (Switzerland) and on the Swiss Federal Disability Insurance files (AI, AVS, IV), a compulsory insurance for all young residents. The study had two aims: firstly, to evaluate the necessary number of institutional beds for people needing multidisciplinary management because of medical, social and educational problems related to severe epilepsy, secondly, to form an idea of the number of epileptic patients needing to be considered for surgical treatment of epilepsy. In fact, we collected only 12 cases requiring multidisciplinary institutional assessment and management due to refractory epilepsy associated with mild or moderate mental handicap. Clinicians dealing with epileptic patients believe that people for whom surgical treatment needs to be considered are rare: the study confirms this rarity. We found this indication to be clearly legitimate in only 7 patients (less than 10% of all epileptic patients).