Background: Attachment theory was conceptualized by Bowlby as relevant across the life span, from "cradle to grave". The research literature on attachment in infants and preschool-aged children is extensive, but it is limited in adolescence. In particular, it is unclear whether or not attachment security is distinguishable from other qualities of the parent-adolescent relationship and predicts adjustment independently of alternate measures of it. Methods: Data from three parallel studies of adolescents, representing normal- to high-risk status, were combined, n = 248. Attachment was assessed using the Child Attachment Interview, a recently constructed measure designed for older children and adolescents. Parent-adolescent relationship quality was assessed in detail through questionnaires, interviews and observation of a standard problem-solving interaction. Adolescent adjustment was assessed through parental psychiatric interview, teacher questionnaire and adolescent self-report. Results: Bivariate analyses showed that secure attachment representations were modestly associated with diverse measures of the current parent-adolescent relationship such as monitoring, negative expressed emotion, and directly observed parental warmth and anger. In addition, attachment representations were reliably associated with key indicators of psychological adjustment in adolescence, including parent-rated oppositional-defiant disorder symptoms and teacher-reported emotional and behavioural difficulties. Regression analyses revealed that secure attachment representations explained unique variance in these indicators of adjustment, independent of alternative measures of the parent-adolescent relationship. Conclusion: Adolescents' representational models of attachment are related to but distinct from current parenting quality and provide unique insight into the understanding of behavioural adjustment. The findings support a distinct conceptual role of attachment representations in adolescence. Clinical assessment and treatment models should include attachment patterns in this age group.