IntroductionCorporeality is an important element of the self structure. Tattoos have been associated with self-esteem, identity diffusion, and aggression.Material and methodsConvicted modified (n = 78; 78.8%) and non-modified men (n = 21; 21.2%) completed the following research tools: the Aggression Severity Scale from the Inventory of Personality Organization (IPO), the Group Identification Scale, the Identity Fusion Scale, a measure of identity fusion, and an agency scale.ResultsBody modifications were a weak predictor (5%) of aggression intensity among male prisoners. About 20% of the study participants, regardless of having a body modification, presented aggression characterized by severe personality pathology.ConclusionsNowadays, body modifications should not be treated as an indicator of severe psychopathology and more aggressive relations with others, including among convicted men. In prisoners who presented high levels of aggression, identity diffusion was observed and treated as a form of adaptation, characteristic for borderline personality integration.