Purpose: This study is to develop the Cultural Competence Scale for Registered Nurses (CCS-RN) and to examine its validity and reliability. Methods: The item pool was generated based on related scales, a wide review of the literature, and in-depth interviews with nurses according to Purnell’s cultural competence model. Content validity was verified by nursing experts. Construct validity using exploratory factor analysis, convergent validity using correlation coefficients, discriminant validity, internal consistency reliability, and test-retest reliability were examined. Results: The CCS-RN consists of a 35-item/7-factor solution with 54.1% of the total variance explained. The convergent validity of CCS-RN was supported. Cronbach’s ⍺ was .94 for the total scale and ranged from .77 to .90 for the seven factors. Test-retest reliability was moderate. Conclusion: The evaluation of the psychometric properties of the CCS-RN shows that this scale is expected to be a valid and reliable measure of cultural competence among nurses. This scale may be useful for assessing nurses’ own cultural competence and thus contribute to strengthening cultural competence.