Borderline personality disorder (BPD) is positively associated with antisocial behavior in adolescent boys and might increase clinical and social problems. Delinquent boys (most with multiple felony adjudications; n = 239) in a residential facility who were high in number of BPD traits (assessed via the Borderline Tendency scale of the Millon Adolescent Clinical Inventory) were compared to 1,197 control offenders in the same facility while controlling for antisocial PD traits. As expected, offenders high in BPD traits had more suicidal behavior and psychopathology features and worse peer and family relations than control offenders and were higher in rates of childhood sexual and physical abuse than controls. Groups did not differ in criminal history. Results suggest that BPD traits are associated with significant problems in functioning and these traits should be identified to help curb associated problems.