Purpose: This study was conducted to evaluate clinical competency of nursing students and to examine the validity and reliability of the scale. Methods: The Clinical Competency Scale was formed through modification of Lee's Clinical Competency Scale that was originally developed in 1990. The Clinical Competency Scale was applied to 203 nursing students. Construct validity, item convergent and discriminant validity, concurrent validity, and internal consistency reliability of the scale were evaluated. Results: Exploratory factor analysis supported the construct validity with a five factor solution; that explained 63.6% of the total variance. Concurrent validity was demonstrated with the Nursing Competence Scale (r=.78, p<.001). Cronbach’s a coefficient for the scale was .96. Conclusion: The results of this study suggest that the Clinical Competency Scale has relatively acceptable reliability and validity and can be used in clinical research to assess clinical competency for nursing students.