The development of the new diagnostic systems (DSM-5; ICD-11) once again generated an interesting discussion around the personality disorders. In this paper we first review the historical traditions, than we examine and compare the new diagnostic suggestions appearing in DSM-5 and ICD-11. Our main goal is to help with the under standing of the new dimensional models and to clarify the questions that arose during the creation of these models. Although the DSM-5 keeps the classic categorical system, it also proposes a hybrid dimensional-categorical diagnostic alternative. Within the hybrid model, the first step is to investigate the impairment of the personality by evaluating the damages to the self and the interpersonal functions. The next step is to form categories along the Big-Five traits. The constellation of the impaired traits dimensions creates the final categories. ICD-11 broke up with the category approach and moved on with the hybrid proposal of DSM-5. Here the first step is to determine the severity of the personality disorder. After that the personality disorder can be specified by a new code. This system does not use the dimensions of the intact personality traits (Big-Five), but the dimensions emerging from the factor analysis of personality disorders. Since in ICD-11 the borderline diagnostic possibility appears in addition to the dimensions, in the last part of the study we review the critical, scientific data of this specific borderline syndrome and its therapy.