In the United States and the United Kingdom, the roles of nurses in antimicrobial stewardship (AS) have been described in guidelines. However, in Japan, no previous studies have clarified nurses' recognition of the role of AS. Moreover, how the AS roles were implemented among nurses in Japan has not been fully clarified. The objectives of this study were to determine the perceptions of infection control nurses (ICNs) in Japan regarding the AS role of nurses and the extent of nurses' practice. A questionnaire survey of ICNs was conducted. Four hundred responses (response rate, 30.8%) were analyzed. Some of the items that have already gained consensus as the AS role of nurses were not recognized as the AS role of nurses by ICNs or had low implementation rates in Japan. Meanwhile, both recognition and implementation rates were high for the 5 types of care proposed. The reason the ICNs agreed that these 5 types of care are AS roles for nurses is that they know that such care can prevent infection and thereby obviate the need for antimicrobial administration. However, whether nurses themselves understand that these are roles for nurses in AS is unclear. To promote AS in Japan, communicating the fact that nurses already contribute to AS, strengthening nurse education, and improving staffing are desirable.