Although establishing a coherent identity is often viewed as a normative developmental task of adolescence, an important question is whether forms of identity disturbance seen in adult personality disorders can also be distinguished in adolescents. If so, such disturbances would constitute an essential target for research and clinical interventions. The goal of this study is to investigate the nature of identity disturbance in an adolescent clinical sample and to explore its links with personality pathology, particularly borderline personality disorder. A national random sample of 139 psychiatrists and clinical psychologists completed a battery of instruments on a randomly selected adolescent patient in their care, including measures of Axis II symptoms and the Identity Disturbance Questionnaire-Adolescent Version, an instrument designed for clinically experienced observers that assesses a wide range of manifestations of potential identity disturbance among adolescents. Factor analysis of the Identity Disturbance Questionnaire--Adolescent Version yielded four clinically and conceptually coherent factors that resembled dimensions previously identified in adults: lack of normative commitment, role absorption, painful incoherence, and lack of consistency. As in adults, identity disturbance in adolescents is a clinically meaningful, multidimensional construct exhibiting significant relationships with different forms of severe personality pathology, most notably borderline personality disorder. As such, identity disturbance can be a manifestation of psychopathology above and beyond the typical Sturm und Drang (storm and stress) of adolescence.