Background: Some members of the general public feel that patients who cause their own organ failure through smoking, alcohol use, or drug use should not receive equal priority for scarce transplantable organs. This may reflect a belief that these patients (1) cause their own illness, (2) have poor transplant prognoses or, (3) are simply unworthy. We explore the role that social acceptability, personal responsibility, and prognosis play in people's judgments about transplant allocation. Methods: By random allocation, we presented 283 prospective (...) jurors in Philadelphia county with one of five questionnaire versions. In all questionnaires, subjects were asked to distribute transplantable hearts between patients with and without a history of three controversial behaviors (eating high fat diets against doctors’ advice, cigarette smoking, or intravenous drug use). Across the five questionnaire versions, we varied the relative prognosis of the transplant candidates and whether their behavior caused their primary organ Results: Subjects were significantly less willing to distribute organs to intravenous drug users than to cigarette smokers or people eating high fat diets (p le; 0.0005), even when intravenous drug users had better transplant outcomes than other patients. Subjects’ allocation decisions were influenced by transplant prognosis, but not by whether the behavior in question was causally responsible for the patients’ organ failure. Conclusion: People's unwillingness to give scarce transplantable organs to patients with controversial behaviors cannot be explained totally on the basis of those behaviors either causing their primary organ failure or making them have worse transplant prognoses. Instead, many people believe that such patients are simply less worthy of scarce transplantable organs. (shrink)