Purpose: The purpose of this study was to develop an instrument for measuring nursing information literacy competency, and then to examine the validity and reliability of the instrument. Methods: The developmental process of the instrument includes construction of a conceptual framework, generation of initial items, verification of content validity, preliminary study, extraction of final items, and psychometric testing. Its content validity was verified by three experts from nursing and nursing informatics. Its construct, convergent, and discriminant validity was examined in confirmatory factor analysis. Finally, its criterion validity was measured with Pearson’s correlation. The tool’s reliability was examined by Cronbach's ⍺. The participants include 382 nurses from four hospitals and one university hospital. Results: Twenty seven items in total were selected for the final scale, and the results of the confirmatory factor analysis were supported with acceptable model fit, which were named competency for identifying problem, potential sources for information, searching fine information, evaluating information, acquising and managing of information, using information ethically, and integrating new information. The convergent, discriminant and criterion validities were also supported. The Cronbach's ⍺ coefficient was .93. Conclusion: The instrument is valid and reliable to comprehensively assess nurses' information literacy competency, and to provide a basic direction for developing nursing information literacy program.