Purpose: The aim of this study was to investigate the effects of occupational stress and coping styles on burnout of clinical nurses. Methods: The participants in this study were 397 nurses, working at the hospitals in Seoul, Gangwon, and Gyongbuk provinces. Data were collected using a structured questionnaire from November, 2009 to January, 2010. The SPSS WIN 13.0 version program was used for data analysis. Results: The most significant predictors of burnout were positive reappraisal and work load. Work load, resource inadequacy, role ambiguity, and indifference coping style positively correlated with burnout. Positive reappraisal and problem-focused coping styles negatively correlated with burnout. Conclusion: The study results indicate that it is important to reduce work load, resource inadequacy, and role ambiguity in nurses and to strengthen their positive reappraisal and problem-focused coping styles to prevent burnout. This could be achieved with job redesign, modification of shift work systems, and by offering burnout prevention program.