This survey concerns the variation in attitudes among European gastroenterologists to truth telling in cases of cancer. Gastroenterologists in all parts of Europe were asked to consider a case of colonic cancer and to state what they would tell the patient and the patient's spouse. 260 replied. Gastroenterologists in northern Europe would usually reveal the diagnosis to both the patient and the patient's spouse, but some would inform only the spouse with the patient's permission. They would sometimes embellish the truth if the cancer had metastasised. Gastroenterologists in southern and eastern Europe would usually conceal the diagnosis from the patient, in many cases even when the patient asked to be told the truth. Most, however, would tell the spouse the full truth about both diagnosis and prognosis. The variation probably reflects differences in both doctors' attitudes and patients' expectations.