Although promising, the available data on nursing practice environments in Japan is extremely limited and there are clear gaps in the literature. Further research is needed using validated instruments to characterize the practice environment and its relationship with patient, nurse, and organizational variables. The purpose of this study was to describe acute-care nurses’ perceptions of the nursing practice environment using the Japanese version of the PES-NWI and examine its association with nurse-reported ability to provide quality nursing care, quality of patient care, and ward morale.