This work presents validation of the Jesness Inventory, particularly its revised version, to the Brazilian reality. It was developed by Carl Jesness, based on his clinical experience and research programs for juvenile offenders, to assess juvenile offenders, particularly to understand the functioning of their personality, offering clues to customize psychosocial intervention, and verification of results from this, in terms of changes in adolescents’ beliefs/values and attitudes. Regarding the psychometric properties, the revised version showed an adequate internal consistency and temporal stability. For the evidence of validity, the results of the concurrent criterion and simultaneous validity were in agreement with those found in other studies, emphasizing the specific capacities of this instrument to distinguish adolescent offenders from non-offenders and properly classify them, denoting its quality in helping the diagnostic process. Research to verify predictive and construct validity is being carried out.