Background: This work aims to present the results of a research study on the relations between work ethic, organizational commitment and job burnout. The authors investigated a sample of employees representing different industries and companies, e.g., lawyers, IT specialists, medical doctors, clerks, teachers and railwaymen (N = 335). Material and Methods: The research study was based on the Job Demands−Resources model. The work ethic measured by the Polish adaptation of the Multidimensional Work Ethic Profile consisted of 8 factors: the value of hard work, work as a central value of life, unwillingness to waste time, aversion to free time, delayed gratification, self-reliance, morality, and work as a moral duty. The organizational commitment measured by the Organizational Commitment Scale consisted of 3 components: affective commitment, normative commitment and continuance commitment. To measure job burnout, the Polish adaptation of the Link Burnout Questionnaire was used, which is composed of 4 dimensions of burnout: psycho-physical exhaustion, relationship deterioration, the sense of professional failure, and disillusion. Results: The study shows that work ethic dimensions and organizational commitment are negatively correlated with job burnout. Significant predictors which can reduce job burnout include work as a moral duty, the value of hard work, work as a central value of life, aversion to free time and morality as dimensions of work ethic and affective commitment. Conclusions: Some dimensions of work ethic and organizational commitment constitute job resources and can decrease job burnout. Work ethic, and affective and normative commitment reduce the sense of disillusion. Med Pr. 2019;70(3):305–16