Purpose: Based on the results of Grandey's Emotion Regulation Process Model and previous studies, this study was conducted to identify the relationship between emotional labor, communication competency, emotional intelligence, social support, and burnout, and to identify factors affecting burnout of nurses in outpatient department. Method: The participants were 190 nurses with more than six months of experience working at the outpatient department of a general hospital in Seoul. Data were collected from April 5 to May 28, 2021, and analyzed using SPSS/WIN 25.0. Results: Significant variables affecting burnout were emotional labor, communication competency, emotional intelligence, education, and total clinical experience. Social support showed a statistically significant negative correlation with burnout, but did not affect burnout. Burnout showed a statistically significant a positive correlation with emotional labor, and showed a negative correlation with communication competency, emotional intelligence and social support. We found a negative correlation between burnout and subjective health status. Emotional labor had a positive effect on burnout. Emotional intelligence, clinical experience for more than 10 years, communication competency, and education for masters or higher negatively affected burnout, respectively. They accounted for 49.2% of the total variance of burnout. Conclusion: Based on the results of this study, it is necessary to reduce emotional labor, one of the major predictors of burnout for outpatient care. In order to prevent emotional labor that results in burnout, an integrated program that improves emotional intelligence and communication competency should be developed.