This paper examined the relationship between job stress and job performance, along with the moderating effect of emotional intelligence (EI) and perceived organizational support (POS) among employees in the Istanbul financial sector. 564 employees and their 78 immediate supervisors were surveyed. The findings of this study suggest that job stress was negatively associated with job per-formance, where EI and POS were able to reduce the effect of stress on job performance. The re-sults largely support the significant impact of job stress on job performance, moderated through EI and POS as hypostasized. This paper demonstrates the important role of the job stress on job per-formance which contributes to conceptual understanding of organizational efficiency. The study has used self-reports- as well as supervisor reports to study the effects of job stress on organizational performance.