To determine critical care practitioners' attitudes about the importance of various factors in decisions to use intensive care, including age, prognosis, quality of life, patient preference, and medical condition. Cohort study. The Annual Educational and Scientific Symposium of the Society of Critical Care Medicine. Participants at the symposium. A self-administered questionnaire was distributed and 600 (52%) of 1,148 registrants attending the symposium responded. Eighty-four percent of respondents were physicians and 11% were nurses. Physicians were internists (30%), surgeons (24%), pediatricians (22%), and anesthesiologists (19%); 58% were in academic practices. Very few respondents believed that age should be a criterion for limiting intensive care (12%). Quality of life as viewed by the patient, probability of surviving hospitalization, reversibility of the acute disorder, and nature of the chronic disorder were the factors that most respondents considered to be important in decisions to admit to the intensive care unit. The patient's social worth, previous psychiatric history, cost-benefit analysis, and cost to society were the factors most respondents considered of little importance. Over 40% of respondents would admit patients with a chronic vegetative state or a patient with metastatic carcinoma and a superimposed, life-threatening event. These results suggest that critical care providers, who must occasionally face difficult decisions about how to distribute limited resources among patients with competing needs, were not often inclined, at the time of this survey, to make choices based on estimates of who might benefit most. These critical care physicians' attitudes about triage may not support the optimal use of critical care resources.