The main goal of the current study is to verify the relationships between emotion dysregulation, mentalization, and romantic attachment in late adolescent girls ( = 120). Adolescence is a very dynamic and sensitive period, in which many changes occur in attachment and emotion regulation. The role of the primary attachment figures is gradually taken over by peers, and the beginnings of the development of romantic attachment are seen. In summary, this study was able to determine that the level of dysregulation of emotions in girls during late adolescence can be partially explained by mentalization and levels of anxiety (though not of avoidance) regarding a romantic partner, though attachment anxiety is more important for explaining emotion dysregulation than the level of mentalization. Only two aspects of emotion dysregulation show relationships with mentalization: nonacceptance of emotional responses and lack of emotional clarity. Adolescence is considered to be a critical period for interventions to protect against the onset of psychopathology. Confirmation of these relationships appears to be important for the design of therapeutic interventions. Our findings may suggest that attachment patterns, mentalization and emotion dysregulation may be good targets for therapeutic intervention in adolescence.