Treatment of borderline personality disorder has some specifics relative to other disorders, which are deriving from nature and structure of those people. Treatment is very slow, often with interruptions, and it presents a special challenge for contratransferal feelings but at the same time offers a possibility of continuous learning, for the patient and the therapist. Main characteristics of this personality disorder are the diffusion of identity, primitive defence mechanisms concentrated around the cleft and relatively preserved ability to rest reality. As classical psychoanalysis and psychoanalytical psychotherapy did not give results in therapy of this disorder, Otto Kernberg took its basic techniques but used them adjusted for borderline personality disorder, developing so called transfer focused psychotherapy. This paper will present the main principles of this modification, applied in practice.