Purpose: The purpose of this study was to investigate the effects of emotional labor, emotional intelligence and social support on job stress in clinical nurses. Methods: Participants were 123 clinical nurses and data were collected from October to December, 2011 and analyzed using descriptive statistics, t-test, ANOVA, Pearson correlation coefficients and multiple regression with SPSS 18.0. Results: A positive correlation was found between job stress and emotional labor. Emotional labor showed a significant negative correlation with emotional intelligence and social support, whereas a positive correlation was found between emotional intelligence and social support. The strongest predictor of job stress was emotional labor. In addition, institution satisfaction (dissatisfaction) and the reason for selecting the job (opportunities for service) accounted for 21% of variance in job stress. Conclusion: The results of this study suggest that it is important to manage emotional labor as well as to improve job satisfaction in order to reduce job stress in clinical nurses.