Considering the fact that banks are the main economic resource in all countries around the world, one of the most significant objectives of the bank is to provide various, expanded, and perfect services for their clients to satisfy them. So, it seems essential to analyze the relationship between the satisfaction of the clients and the functions of the banks. This case study deals with the study of the branches of Bank Saderat in the province of Qazvin. This study aims to investigate the effective factors in satisfying the clients, and finally the level effectiveness of these factors is determined, and the possible solutions for the increase in the level of satisfaction of the clients are investigated.