The objective of this research is to analyze the mediating effect of job satisfaction on the relationship between perceived organizational support (POS) and job performance for white-collar employees in an energy sector in İstanbul. The survey was distributed to 964 employees, while 700 valid questionnaires were included within the scope of the analysis. Exploratory factor analysis (EFA) was carried out to determine factor distribution, while confirmatory factor analysis (CFA) and reliability analysis were carried out to detect scale validities and reliabilities. Relations between scale variables were examined by a correlation analysis. Structural equation model (SEM) was constructed based on research hypotheses while the effect of POS on job satisfaction, the effect of job satisfaction on job performance and the mediating role of job satisfaction on this relation were tested through this model. All hypotheses are supported in this study.