Version 2 of the accreditation, known as “certification” in the law of August 13, 2004 law, introduces assessment practices. The opportunity to introducing these practices offers to the whole health profession the possibility of using concretely, in their practices, the results and knowledge of healthcare research. Taking a dual approach (research and process quality), the research aims to analyze the knowledge, attitudes, and practices associated with the Léonetti Law (Act no. 2005-370 of April 22, 2005, in reference to patients’ rights and the end of life), among health professionals. 1,770 such professionals, working at Toulouse University Hospital, have answered inquiries, which included questions about professional knowledge (confidence figures, advanced directives) as well as questions linked with professional practices (attitudes, behaviors, decisions taken). The results indicate a certain consensus on professional practices: good knowledge about the notion of confidence figures, changes in reply rate about the discriminating variable “seniority,” and new emerging professional attitudes. This kind of research underlines the deep links between knowledge systems and the attitude required in palliative care.