The aims of this study were (a) to investigate the presence of clinically significant personality traits and personality disorders (PD) in patients living in residential facilities, with or without a history of violence (69 and 46, respectively); and (b) to investigate any associations between clinically significant personality traits and PDs, aggression, impulsivity, hostility, and violent behavior during a 1-year follow-up. The most frequent primary diagnoses were schizophrenia (58.3%) and PD (20.9%). Those with a history of violence demonstrated more antisocial and alcohol dependence features and lower depressive PD symptoms than the control group. Hostility levels, antisocial symptoms, and drug dependence, as well as a Structured Clinical Interview for DSM-IV Axis II diagnosis of PD, predicted aggressive and violent behavior during follow-up. The study confirms the relevance of assessing PDs both to evaluate the risk of violent behavior and to plan appropriate preventive and treatment intervention.