An organization's success in today's competitive business environment is mainly based on human capital and banking institutions andthere is no exception to this. Satisfied and loyal employees are the most important assets of an organization, and primarily responsible for productivity and profitability. This study examines the level of employee satisfaction in the National Bank of Greece and attempts to identify the contributing factors. The survey covered 366 employees in Greek branches of the National Bank of Greece, and was conducted with the use of a questionnaire. The analysis of the results indicated moderate levels of job satisfaction in the majority of employees while the main factors contributing to job satisfaction were collegial relationships and relationships with superiors. By contrast, the promotion policy and potential empowerment and participation, may probably need improvement and corrective measures as they not only don't constitute a source of satisfaction for the employees of the National Bank of Greece, but fluctuate within the limits of neutrality and discontent.