AbstractThe meaning and the practice of truth‐telling have undergone many changes throughout western European history. Although Plato noted the conflict between the idea of protecting individuals from information which could frighten them and the idea of respecting their autonomy and freedom to know, Greek physicians displayed a more pragmatic attitude. In contrast, the Catholic church has always condemned any form of lying. The emergence in the Middle Ages of the notion that Catholics had to receive the sacrament of extreme unction in order to ensure salvation made it necessary to inform patients of the approach of death. But the gradual decline of the Church's influence since the eighteenth century led to the increasing practise of telling medical ‘white lies’. Rapid changes are occurring, however, in light of medical progress, evolving ethical beliefs and major sociological changes, especially the increasing role of the media. In fact, the medical ‘secret’ is shared by many people and the problem is no longer whether physicians must tell the truth but how to tell it. Patients often do not understand the information they are given because the words are too esoteric. Failures in physician/patient communication arise also because of the phenomenon of denial, which is a part of the normal adaptation process. The physician has the responsibility of making the decision and of imparting to the patient a sense of innovation and