This study aims to increase the knowledge on relations between corporate social responsibility (CSR), employee commitment, and firm performance in Serbia. The theoretical part of the article analyzes the relations between CSR and firm performances, as well as CSR and employee commitment, based on available world-wide research results. The empirical part of the article presents the research results for large companies in Serbia, regarding the relations between CSR and firm performance, CSR and employee commitment, and the mediating role of employee commitment on the relationship between CSR and firm performances. The sample consists of 53 large companies, each with more than 250 employees. The database was compiled between October 2019 and March 2020 using self-developed questionnaires. PLS-SEM analysis was implemented to uncover the relationship that exists between the variables. The authors determined that there was no direct effect of CSR on firm performances, but positive, statistically significant effects on employee commitment. Although the direct effect is missing, employee commitment has a positive mediation effect on CSR-firm performance link. The concluding part of the article outlines the theoretical and practical implications, acknowledges research limitations, and offers future research directions.