This descriptive research study investigated the mediating effect of positive psychological capital (PPC) on the relationship between emotional labor (EL) and job satisfaction (JS) of clinical nurses. The data was collected from 274 nurses working for two hospitals in the D city, Korea, from 7 Sep. 2016 through 23 Sep. 2016. General characteristics, EL, JS, and PPC were surveyed using structured questionnaires. Statistical analysis was performed using descriptive statistics, ANOVA, and stepwise multiple regression analysis with SPSS/WIN 21.0. The mediating effect of PPC on the relationship between EL and JS was tested using Baron & Kenny's 3-step hierarchical regression analysis. There were negative correlations between EL and JS (r=-.36, p<.001) and EL and PPC (r=-.25, p<.001) and a positive correlation between JS and PPC (r=.47, p<.001). In addition, the PPC, had a partial mediating effect (z=-3.44, p=.001) on the relationship between EL and JS. It is proposed, based on the results, to develop an organized intervention program that enhances job satisfaction by reducing emotional labor and strengthening positive psychological capital in clinical nurses.