This paper determines the weights of the key factors for evaluating the performance of the banking system in Iran using the Balanced Scorecard (BSC) and Fuzzy Analytic Network Process (FANP) approaches. This paper first identifies key factors for the performance evaluation and then determines the cause-and-effect relationship between using the DEMATEL approach. The key factors were included in the BSC framework using the experts' opinions and following principles, including the need for all communication to lead to profitability, not considering the causal relationship from more tangible dimensions to intangible dimensions, and eliminating feedback causal relationships. The calculated weights show the maximum importance of the learning and growth dimensions and the minimum importance of the financial dimension. Among the key factors, on-time service is the maximum important, with customer retention being the minimum important. The extracted key factors can evaluate the performance of the country's banking system descriptively and based on the data obtained from declarations or official reports provided by different evaluators.