This study aims to identify and rank the key impediments to blockchain implementation in Iran's banking industry. Despite its potential to enhance transparency, security, and operational efficiency, blockchain adoption faces multiple challenges. To systematically analyze these barriers, a mixed-method approach combining the Fuzzy Delphi Method (FDM) and the Decision-Making Trial and Evaluation Laboratory (DEMATEL) technique was employed. Initially, expert interviews and a literature review were conducted to identify relevant barriers. Subsequently, the FDM was applied to assess their significance based on expert opinions, followed by the DEMATEL technique to determine the causal relationships and prioritize the barriers accordingly. The study targeted 30 industry experts, including banking managers, technology specialists, and blockchain professionals, selected through purposive sampling based on their expertise. Findings revealed that scalability limitations, high implementation costs, and regulatory uncertainty represent the most critical challenges. Moreover, the causal analysis indicated that integration with legacy systems and data privacy concerns serve as root causes, whereas resistance to change and high initial investment costs emerge as consequence-driven barriers. These insights highlight the need for strategic interventions to address fundamental obstacles and facilitate blockchain adoption in Iran’s banking sector.