More than 32.000 children are adopted internationally every year; about one hundred countries around the world are involved (Selman, 2000). The literature provides strong evidence that the exposure to early stress influences later emotion regulation. Regarding adopted children, early stress, poor life conditions and separation may constitute potential risk factors regarding their socio-emotional development, and the period of adolescence, which involves separation experiences and new relationships may be especially sensitive in this regard. While most studies on attachment and behaviour problems in adopted children (i.e. younger than 11 years of age) provide relatively optimistic results, there are only few studies addressing these issues in adolescents who had been adopted in infancy or in childhood. The present project will investigate adopted and non-adopted adolescents’ attachment, socio-emotional adjustment and behaviour problems, and the parents’ representations about their children. It is hypothesized that adolescents adopted in infancy or in childhood present more often behaviour problems, and that the emergence of these problems is mediated by the adolescent’s attachment representations, which in turn are influenced by the characteristics of the adoption (i.e. age at adoption, number of placements and early attachment difficulties), by the parents’ representations of their children and by cultural factors. Adopted adolescents are over-represented in psychiatric consultations. A better understanding of these mechanisms may help preventive efforts.