Nowadays, many people do not know much about the members of the Institute of Royal Physicians (Thai y vien) except for scattering information in the Nguyen Dynasty's history books or family documents, but they are only related to several persons. This paper introduces an official document under the reign of Emperor Minh Mang fully providing the names, native places, service duration of the members of Institute of royal physicians at the time of the first regnal year of Emperor Minh Mang (1820). This document allows us to partly visualize the operation of the agency responsible for the health of the royal family, then to continue to learn about health care activities under the Nguyen Dynasty.