The aim of the article is to try to integrate the clinical work, theoretical knowledge, and scientific research in the context of the latest mentalization theories. The theoretical and practical basis for considerations on mentalization is Otto Kernberg's concept of personality organization and the psychotherapy system for patients with personality pathology − Transference Focused Psychotherapy (TFP). In the article, the issue of diagnosis of patients’ mentalization along with the level of personality organization is discussed. Possible mentalization disorders appearing in the patient-therapist relation (pseudomentalization, concrete mentalization and lack of mentalization) are also described. Moreover, the latest research on mentalization in the context of psychodynamic psychotherapy is presented, concerning two aspects of mentalization: as the function of the therapist and the patient. The last part of the article refers to the importance of mentalization as a therapeutic factor in TFP. Conclusions: Mentalizing can be seen as a certain independent attitude, a specific meta-theoretical basis of the therapy, followed by techniques resulting from a specific paradigm. Psychodynamic psychotherapy is intended to provide maximum comfort of mentalizing for both the patient and the therapist.