In the field of developmental research, there is a pressing need to develop clinically sounded and empirically grounded tools for the assessment of personality development in adolescence. After a review of the relevant literature on adolescent personality disorders we present through empirical data and clinical material the IPOP-A, a semi-structured interview for adolescents ranging from 13 years old to 21 years old. The IPOP-A seems to be promising to gather information about processes that constitute the building blocks of adolescent personality organization. Keywords: Adolescent personality disorders, assessment, borderline personality organization, IPOP-A, personality development, semi-structured interview