Social changes and developments in medical science prompted mental health professionals to adopt new roles in relation to their self-disclosure practices. The physician-patient relationship has balanced on a different level, promoting the equity and the autonomy of the second. The contemporary patient is better informed, asks more questions and requires more answers. The boundaries between "professional" and "personal" are less strict and patients believe that they have a right to know whether the personal experiences (educational, clinical, research) of their therapists enable them to understand and help them. Although the latest version of the American Psychological Association's Ethics Code (APA, 2002) offers no explicit guidance on therapist self-disclosure, it incorporates an implicit message that therapists can no longer choose non-disclosure without having considered the issue carefully. Non-disclosure is no longer the easy answer, as it may affect adversely the therapeutic relationship and the therapeutic effect. These new circumstances prompted representatives of all psychotherapeutic orientations to reconsider traditional positions on therapist self-disclosure, to adapt to the diverse needs of the patients and the modern requirements of the therapeutic process and to define the framework within which its conduct is not only safe but also effective. This review attempts to describe the concept of therapist self-disclosure and its use and its functions in Cognitive-Behavioral Therapy, following a history of the term in other major therapeutic schools (psychoanalytic, client-centered and systemic). As the focus of any psychotherapy is the patient himself, we added reports of patients' experiences by their therapists' disclosures. Those descriptions reveal clearly not only the benefits of therapist self-disclosure but also the dangers posed by improper use. Finally, we attempt to set a framework in the form of proposals, as these result from existing empirical and theoretical research. As therapists will inevitably be confronted with the issue of self-disclosure in their careers, they will have to make decisions on if, what, when, why, to whom, and how to disclose. These guidelines aspire to be of help to therapists so they can use self-disclosure efficiently and ethically and to minimize potential risks.