We studied the extent to which 82 private physicians and 75 house officers talked with hospitalized patients or their families (or both) about whether they would desire cardiopulmonary resuscitation if it became necessary. During the period of study (1981), 154 patients were resuscitated at our university teaching hospital. In 68 per cent of the cases, physicians had formed an opinion about the patient's attitude toward cardiopulmonary resuscitation. However, only 30 (19 per cent) of the patients had discussed resuscitation before the arrest with either their private physician or a house officer (or both); 51 (33 per cent) of the families were consulted. These percentages did not differ significantly according to the underlying disease, whether the patient was on the general wards or in the intensive-care unit, the physician's estimate of the probability of arrest, or the physician's level of training. Even the 151 physicians who believed that patients should participate in decisions about resuscitation, actually discussed the issue with their patients only rarely. We interviewed the 24 competent patients who survived cardiopulmonary resuscitation, to compare their actual attitudes about resuscitation with their physicians' opinions about their attitudes. The physician's opinion about a patient's desire for resuscitation correlated only weakly with the preference expressed by the patient. We suggest that physicians and patients consider the benefit of open discussion about cardiopulmonary resuscitation.