This chapter addresses: why the patient perspective is impor-tant for DUR researchers; how patients perceive medicines; some relevant issues for the quality use of medicines; and sug-gestions on how to research the quality use of medicines from the patient perspective. It does not provide a comprehensive guide to conducting research involving patients. There is a huge gap between how health systems and health professionals understand and measure the quality use of medicines and how patients (or the public) perceive medicines. Even when “so-called” scientific rationality is clear, policymakers, health professionals, and researchers need to recognize and accept that no policy or intervention involving treatments, care, and services will be successful unless the patient perspective is recognized, acknowledged, respected, and understood. Involving patients in developing interventions to assure or improve the quality use of medicines may also help improve the implementation of these interventions and can assist health professionals, policymakers, and industry in identifying different.