PURPOSE: The purpose of this study was to identify the effects of emotional labor and self-efficacy on psychosocial stress of nurses. METHODS: A cross-sectional correlation study design was used. The participants were 186 nurses from two general hospitals in Jeju Island, South Korea. A self-report questionnaire was used to collect data including data on emotional labor, self-efficacy, and psychosocial stress. Data were analyzed using descriptive statistics, Pearson correlation coefficient, t-test, ANOVA, and hierarchical multiple regression. RESULTS: Approximately 98% of the participants were categorized as having potential and high risk stress levels. Hierarchical multiple regression showed that employment status, surface-acting, and self-efficacy explained 37.0% of psychosocial stress and self-efficacy was the main factor influencing psychosocial stress. CONCLUSION: Nursing administrators should understand that nurses suffer from high risk stress and emotional labor. To reduce the psychosocial stress of nurses, there is needed to improve stressful work conditions such as irregular employment, decrease surface-acting, and improve self-efficacy.