Blockchain technology, due to its prominent features such as information transparency, high security, data immutability, and the ability to eliminate intermediaries, has the potential to transform the banking industry. By creating a distributed ledger, this technology enables secure, fast transactions without the need for central authorities, which can reduce operational costs and improve the efficiency of banking systems. This research was conducted to identify and determine the significance of critical success factors of blockchain technology in the banking industry, aiming to help banks effectively leverage this emerging technology. First, critical success factors were identified through a comprehensive literature review, and then they were screened using the fuzzy Delphi technique. Subsequently, the importance of each factor was calculated using the Bayesian best-worst method, a multi-criteria group decision-making approach. The findings indicated that high scalability and fast transaction processing speed, security and standardization of blockchain technology, and interoperability with existing systems are among the most critical success factors. Finally, based on the results and with the goal of improving the efficiency and security of banking systems, practical and research recommendations were provided.