Background: Data are lacking regarding the perception of cancer patients’ prognosis by physicians who are not oncologists. Methods: This was a multicenter survey of seven university-affiliated hospitals, assessing physicians’ perception of the median survival of patients with seven advanced malignancies. The study cohort included physicians from all 73 internal medicine, surgery, emergency medicine and critical care departments in the participating hospitals. Family practitioners were contacted through email. Physicians’ specialty, age, professional status and hospital type (secondary vs tertiary) were noted. The primary end-point was defined as the percentage of answers with a pessimistic error of more than a year in perception of prognosis as compared with current literature. The secondary end-point was defined as any pessimistic answer. Results: Four hundred and eighty-eight physicians filled the questionnaire, including 429 hospital physicians and 59 family practitioners. Perception of prognosis was pessimistic when compared with current literature, with 37% and 59% of the answers meeting the primary and the secondary end-points, respectively. Younger age, resident status and work at a secondary hospital were associated with pessimistic perception (P<.001 for all variables). Pessimistic outlook was similar for all specialties and for most malignancies, including those with considerable cure rates such as Hodgkin's lymphoma and germ cell tumour. Conclusion: Non-oncologists are considerably over pessimistic regarding their perception of the cancer patients’ prognosis. A pessimistic perception of prognosis might cause undertreatment and therefore affect both patients’ quality of life and their actual survival. Education regarding cancer therapy and its benefits should be emphasised for non-oncologists involved in cancer patient care.