In the last years, the dimensional classification of Personality Disorders and the development of manualized treatments have contributed to a new conceptualization of these disorders. Therefore, it is necessary to implement evidence-based clinical treatments and good practices, through the application of international guidelines for the treatment of personality disorders. This paper aims to analyze the main guidelines from recent literature regarding the treatment of Borderline Personality Disorder (BPD) and Antisocial Personality Disorder (ASPD) and to identify which are the recommended treatments with greater efficacy. For this reason, two of the most authoritative sources of international guidelines were examined: National Institute for Health and Care Excellence (NICE) and the American Psychiatric Association (APA). Furthermore, given the need to provide updated scientific evidence, in addition to the guidelines, recent reviews and meta-analyses on the treatment of disorders in question were considered. In conclusion, the literature suggests that clinicians pay greater attention to the dimensional aspect of personality disorders within the psychotherapeutic intervention because it allows the use of specific traits and domains for setting up a more targeted intervention.