Purpose: This study is a descriptive research study to determine the level of professional autonomy, professional self-concept, and job satisfaction of emergency nurses, and to investigate their correlations and verify the effects of professional autonomy and professional self-concept on job satisfaction. Method: The subjects were 189 emergency nurses with a work experience of 1 year or more, in 14 hospitals located in B and U Metropolitan Cities. The study was conducted from July 20, 2014, to August 30, 2014. The measurement instruments for professional autonomy, professional self-concept, and job satisfaction were used as the measurement tools. The collected data were analyzed using the t-test, analysis of variance, Scheffe's test, Pearson's correlation coefficient, and multiple linear regression. Results: Job satisfaction among emergency nurses showed a significant positive correlation with professional autonomy (r=.28, p <.001), and with professional selfconcept (r=.50, p <.001) with sub-areas of professional practice (r=.79, p <.001), satisfaction (r=.64, p <.001), and communication (r=.25, p <.001). Factors affecting job satisfaction were satisfaction (${\beta}$=0.60, p <.001), followed by low professional autonomy (${\beta}$=-0.24, p <.001) and communication (${\beta}$=0.14, p =.008), which accounted in total for 48.3% of the effect. Conclusion: This study suggests that enhancing professional satisfaction, maintaining proper communication, and securing autonomy are required to improve the job satisfaction among emergency nurses.