Purpose: The purposes of this study were to investigate moral distress, job satisfaction and turnover intention of mental health nurses, and identified influencing factors on mental health nurses' turnover intention. Methods: A descriptive survey was conducted with 85 mental health nurses working in mental medicine department closed wards of 5 hospitals in Busan Metropolitan City and Gyeongsangnam Province. Data were collected from December 1, 2015 to January 31, 2016 and analyzed using percentage, frequency analysis, average, standard deviation, t-test, ANOVA, Pearson correlation coefficient and multiple linear regression analysis, with SPSS/WIN 18.0. Results: 1) Moral distress had a statistically significant positive relationship with turnover intention (r=.24, p=.023). Job satisfaction had a statistically significant negative relationship with turnover intention (r=-.45, p<.001). 2) Moral distress had a positive effect on turnover intention (β=.23, p=.018), and job satisfaction, a negative effect on turnover invention (β=-.44, p<.001). These variables explained 24.0% of the variance. Conclusion: Findings indicate that moral distress and job satisfaction are important variables influencing turnover intention in mental health nurses. Development and provision of intervention programs to reduce moral distress and increase job satisfaction will help to decrease nurses' turnover intention.