A sample survey of the public in a midwestern state substantiates the existence of widespread challenges to the authority of physicians, a phenomenon previously reported only impressionistically in the media. Attitudes tending to reject physicians' right to direct their interaction with patients characterized more than half the sample and were related to younger age, higher educational level, and greater health knowledge, with a consumerist and anti-authority stance also explanatory. Actual challenging behavior occurred at least once for about half the group, but in this instance was related less to age and knowledge than to more extensive experience with the health care system, as well as a lack of trust in people in general and doctors' competence in particular. However, explained variance was modest, arguing that other variables, not identified in this study, are at work. Surprisingly, respondents' health status, race, sex, and pattern of insurance coverage had little impact on either attitude or behavior, while both knowledge and a general tendency to reject authority were influential factors. Implications for physician-patient relations in the future are discussed in light of a number of social changes, including the rising educational level of the American public.