Objective To examine the attitudes of US patients about the use of placebo treatments in medical care. Design One time telephone surveys. Setting Northern California. Participants 853 members of Kaiser Permanente Northern California, aged 18-75, who had been seen by a primary care provider for a chronic health problem at least once in the prior six months. Results The response rate was 53.4% (853/1598) of all members who were eligible to participate, and 73.2% (853/1165) of all who could be reached by telephone. Most respondents (50-84%) judged it acceptable for doctors to recommend placebo treatments under conditions that varied according to doctors’ level of certainty about the benefits and safety of the treatment, the purpose of the treatment, and the transparency with which the treatment was described to patients. Only 21.9% of respondents judged that it was never acceptable for doctors to recommend placebo treatments. Respondents valued honesty by physicians regarding the use of placebos and believed that non-transparent use could undermine the relationship between patients and physicians. Conclusions Most patients in this survey seemed favorable to the idea of placebo treatments and valued honesty and transparency in this context, suggesting that physicians should consider engaging with patients to discuss their values and attitudes about the appropriateness of using treatments aimed at promoting placebo responses in the context of clinical decision making.