For many years, clinicians, especially those working in rehabilitation centers for alcohol and drug users, have been preoccupied with clients presenting with dual diagnosis: substance abuse and legal problems. Comparative analyses of three groups of addicted men, 553 offenders and 499 nonoffenders in treatment for addiction problems and 103 addicted inmates were made to ascertain the biopsychosocial profile of these persons. Results showed that dual-diagnosis clients experienced more severe biopsychosocial problems than the nonoffending group of subjects. Offenders in prison experienced more social maladjustment than offenders in drug addiction treatment, they were less preoccupied by their drug consumption, and less motivated to change. Implications for treatment are discussed.