Although theories on meta-cognition and self-monitoring imply the importance of meta-cognition in patient—physician interactions, there is no evidence to support this hypothesis. Thus, we evaluated patient and physician perceptions of the level of a physician's explanation and explored the possible influence of patient meta-cognition on patient responses to physicians. We conducted a questionnaire survey of 579 internist—patient pairs in Japan. The findings show that patient meta-cognition, and not perception, of the sufficiency of a physician's explanation plays a critical role in determining extreme patient responses to a physician, such as ignoring the physician's advice and doctor-shopping, whereas patient perception is a predictor of milder patient responses such as patient understanding and satisfaction.