A case is described of a fifty year old single man who made disclosures about criminal sexual practices during a psychiatric assessment. In common practice with other professional men, a doctor is under a duty not to disclose, without the consent of his patient, information which he has gained in his professional capacity other than in exceptional circumstances. We discuss the ethical and legal considerations surrounding issues of medical confidentiality and the dilemma that sometimes face clinicians, when they feel obliged, in the public interest, to disclose information they have gained in confidence. Breach of confidences can have deleterious consequences; particularly for the doctor-patient relationship, but failure to disclose in some situations could have serious implications for the well-being of the wider society. Doctors should be aware of the basic principles of confidentiality and the ethical and legal framework around which they are built.