It has populated the laws, without forgetting the notable record of focusing above all on the conditional suspension of the execution of the sentence. In the post-war penal system, prison lost ground in favor of sentencing and fines. Even if in some countries the use of prison as a means to eliminate crime persists or advances, with a very strong emphasis. Alternatives and substitutes fuel the most important intervention in the system of criminal sanctions. Therefore the incarcerations of the substitute do not exempt from the purpose inherent to the penal system as a whole. The crisis of the penal system and in particular of the adequacy and effectiveness of punishments sees prison as a substitute. The success or failure of these calls into question, for multiple purposes, the relevance of a penal system inspired by declamatory ideals and removed from strictly repressive orientations and temptations. This is not only to reduce the number of prisoners but also to achieve good results, as the current humanistic and democratic disciplinary system promises. The purpose of this proposal is to determine how effective prison or disciplinary rehabilitation is