This article presents an approach to the evaluation of patient-held beliefs and behaviors that may not be concordant with those of biomedicine. Physicians and patients often hold discrepant models of health and illness that may affect the effectiveness of communication during the clinical visit. An extreme example of such a discrepancy exists when the patient feels that he or she has an illness that is not defined within the biomedical paradigm. These are commonly referred to as folk illnesses. An example of such an illness is provided in order to discuss the effects of folk beliefs on patient-held perceptions of health and sickness, treatment-seeking behavior, clinical care, and physician-patient communication. Guidelines for addressing clinical issues surrounding folk beliefs and behaviors in a culturally sensitive way are discussed.