This article deals with training in professional ethics, a training that has greatly developed in Quebec during the last 30 years. After having exposed the ‘raison d’être’ of such training and its aims, we argue that nowadays this training usually integrates knowledge, know-how, know-how-to-be, and know-how-to-become. As we present it, the aims of the training in professional ethics are to provide a holistic development of the person. Therefore, two aspects are indispensable: the training of professional judgment and the development of the moral sensitivity of the professional as a person.