Purpose: The purpose of this study was to develop a measurement tool for a positive nursing organizational culture and to verify its reliability and validity. Methods: A conceptual framework and construct factors were extracted through an extensive literature review and indepth interviews with nurses. The final version of the preliminary tool for the main survey was confirmed by experts through a content validity test and a preliminary survey of 40 nurses. Subsequently, the final tool was developed using a validity and reliability test containing 43 preliminary items. The final version of the tool was used with 327 hospital nurses in the testing phase for the main survey to assess validity and reliability. Results: From the factor analysis, 4 factors and 26 items were selected. The factors were positive leadership of the nursing unit manager, pursuit of common values, formation of organizational relationships based on trust, and a fair management system. The entire determination coefficient was 67.7%. These factors were verified through convergent, discriminant, and concurrent validity testing. The internal consistency reliability was acceptable (Cronbach’s α = .95). Conclusion: Both the validity and reliability of the scale were confirmed demonstrating its utility for measuring positive nursing organizational culture. It is expected to be used for education, research, and practical performance policies regarding the nursing organizational culture.