The chapter seeks to demonstrate and describe, from a critical perspective, the most widespread treatment models and programs for sex offenders in prison, opting for integrated approach based on risk assessment and the evaluation of their psychological and social characteristics. Furthermore, specifying factors that can affect the success of the treatment leads to the conclusion that sex offenders require the implementation of differentiated programs focused on their personal characteristics and needs. The reduction of recidivism is indicated as a criterion with which to assess the effectiveness of the programs, although the results achieved in research on the matter do not always agree and do not always confirm a reduction in repeat offenses in the subjects undergoing treatment. The chapter concludes by calling for greater program development and more precise methodological accuracy in verifying the results.