This study aims to examine the effects of ethical decision-making in school counselors on burnout through the self-efficacy of ethical practice and whether the relationship between such factors is regulated by the work environment. The study participants involved 242 counselors working in elementary, middle, and high schools, and the school board. The collected data were analyzed using SPSS and PROCESS macro for correlation analysis, mediation model analysis, and conditional process analysis. The results are as follows. First, evidently, the higher the ability of an individual to discern appropriate coping behaviors in an ethical dilemma situation, not to mention a lower rate of burnout. Second, the mediating effect of self-efficacy in one s ethical practice in the relationship between ethical decision-making and burnout were found to be significant. Third, job demand and resources were identified as the regulatory factors of ethical decision-making and self-efficacy in one s ethical practice. Fourth, the adjusted mediating effects of job demand and resources on the effects of ethical decision-making on burnout, through self-efficacy in one s ethical practice, were found to be significant. This study revealed that moderating and adjusted mediated effects were not significant in instances where job demand was low and job resources were high. Strategies to prevent burnout among professional counselors were also discussed.