Purpose: The purpose of this study was to examine self-efficacy, nursing professionalism, organizational commitment for nurses and the mediating effect of nursing professionalism on the relationship between self-efficacy and organizational commitment. Method: Data were collected by questionnaires from 185 nurses in hospitals from June 10 to August 30, 2010. Data were analyzed by Pearson"s correlation coefficient and multiple regression procedures. Result: 1. The nurses investigated attained a mean of 4.77 and 3.37 on self-efficacy and organizational commitment respectively. They attained a mean of 4.55 on nursing professionalism. 2. Correlation among self-efficacy and nursing professionalism had a positive correlation to organizational commitment 3. Nursing professionalism had a mediating effect on the relationship between self-efficacy and organizational commitment. Conclusion: Self-efficacy exerted an influence on organizational commitment through the mediating effect of nursing professionalism and is expected to lay the foundation for the promotion of organizational commitment.