The therapeutic relationship is crucial in a long-term therapy. Some authors claim that it is the most important factor of the treatment. What are its determinants? What factors decide about the fact whether it is formed or not? What is the importance of creating a relationship with a BPD patient? Is forming a therapeutic relationship, based on trust, with a BPD patient a condition of the therapy or its significant phase and success? What are difficulties and constraints in constructing therapeutic relationships with those patients? What is the experience of therapists in different aspects of therapeutic relationship with this type of patients like? Which reactions of a psychotherapist support forming a good relationship and which ones make it difficult? The aim of this article is to search for the answers to these questions, basing on a selection of publications, contemporary research and the experience of psychotherapists. The factors related to BPD patients, simplifying forming a therapeutic relationship and hindering this process, are going to be described. There are going to be analysed also benefits possible to be achieved by a BPD patient with disturbed interpersonal relationships, who manages to build a secure therapeutic relationship.