This paper seeks to identify the priority of factors affecting the quality of banking services in Bank Saderat Iran for better allocation of resources to enhance the quality of its banking services. The study develops a fuzzy method to handle uncertainty associated with the data and using analytical network process (ANP) ranks different factors influencing on service quality. The results have indicated that the quality of e-services (ESQ) is the most important factor followed by the quality of banking services agility (ASQ), the service system quality (SSQ), and the behavioral service qualities (BSQ). Moreover, the employees’ competence and skills, the reliability of the electronic system and the reliability of the service system, an impeccability banking system integrity and accountability instruments are among other effective factors influencing on the quality of banking services.