The purpose of the study was to assess the effects of the cognitive-behavioral intervention program “Taking steps towards peace”, which has the aim of promoting respect for human rights and preventing violence. We used an experimental posttest design with an equivalent control group. The sample comprised 276 adolescents from 15 to 17 years of age (M= 15.55, SD= 0.70), 191 experimental subjects and 85 controls. The intervention consisted of ten 90-minute sessions. To assess the dependent variables a self-inventory was used: the questionnaire assessment program, adolescents version (CEP-A). The results of the ANOVAs confirmed that the program promoted significant improvement in eight socio-emotional dimensions: communication, social behavior, self-concept/concept of others, emotions, violence, conflict-solving, prosocial values/human rights, and psychological well-being. The relevant role of programs carried out with adolescents for the prevention of violence is discussed.