Résumé : Patients wish to be fully informed about their health, but some information and its disclosure may pose special challenges depending on the severity of the illness. This prospective observational study investigates the content of information about the disease and treatment, as well as the process by which information is disclosed as part of 51 consultations with people with malignant gliomas. Patients and their relatives were fully informed of the diagnosis and treatments (types, risks, practical details), but disease progression with and without treatment, like the prognosis, was rarely addressed. Relatives were more likely than patients to ask questions related to the severity of the illness and the prognosis, leaving doctors in the difficult position of determining whether and how the information may be disclosed. Ethical issues related to informed consent are discussed in light of an incurable disease with a fast progression.