Most patients admitted to the intensive care unit are unable to participate in decisions relating to their care. Therefore, physicians have to inform relatives on the condition of the patient, his evolution and the estimated prognosis. Numerous studies have shown that relatives commonly have inaccurate expectations of the patient’s prognosis, due to either misunderstanding of oral information by the physicians and/or overly optimistic beliefs. This may lead to undue prolongation of an ICU stay in the case of a poor prognosis. Several methods have been proposed in order to align relatives with the estimation of the patient’s prognosis by the physicians. The use of visual tools, added to oral information seems beneficial. Moreover, communication with relatives on the prognosis has to convey support and empathy.