ABSTRACT: The broad diversity in physicians' judgments on controversial health care topics may reflect differences in religious characteristics, political ideologies, and moral intuitions. We tested an existing measure of moral intuitions in a new population (U.S. physicians) to assess its validity and to determine whether physicians' moral intuitions correlate with their views on controversial health care topics as well as other known predictors of these intuitions such as political affiliation and religiosity. In 2009, we mailed an 8-page questionnaire to a random sample of 2000 practicing U.S. physicians from all specialties. The survey included the Moral Foundations Questionnaire (MFQ30), along with questions on physicians' judgments about controversial health care topics including abortion and euthanasia (no moral objection, some moral objection, strong moral objection). A total of 1032 of 1895 (54%) physicians responded. Physicians' overall mean moral foundations scores were 3.5 for harm, 3.3 for fairness, 2.8 for loyalty, 3.2 for authority, and 2.7 for sanctity on a 0-5 scale. Increasing levels of religious service attendance, having a more conservative political ideology, and higher sanctity scores remained the greatest positive predictors of respondents objecting to abortion (? = 0.12, 0.23, 0.14, respectively, each p<0.001) as well as euthanasia (? = 0.08, 0.17, and 0.17, respectively, each p<0.001), even after adjusting for demographics. Higher authority scores were also significantly negatively associated with objection to abortion (? = -0.12, p<0.01), but not euthanasia. These data suggest that the relative importance physicians place on the different categories of moral intuitions may predict differences in physicians' judgments about morally controversial topics and may interrelate with ideology and religiosity. Further examination of the diversity in physicians' moral intuitions may prove illustrative in describing and addressing moral differences that arise in medical practice.