Identifying and assessing potential risks of implementing new technologies is critical for organizations to respond to them efficiently during the technology life cycle. Blockchain has been introduced as one of the emerging and disruptive technology in the field of information technology in recent years, which system developers have noted. In this study, a comprehensive set of risks have been identified and categorized based on the literature findings to identify the risks of blockchain implementation. Critical risks are defined by performing a two-stage fuzzy Delphi method based on the experts' opinions. Then, possible causal relationships between considered risks are identified and analyzed using the fuzzy cognitive mapping method. Finally, the most important risks are ranked based on the degree of prominence and the relationships between them. Industry enterprise resource planning system based on blockchain technology has been studied as a case study. The obtained results indicate that the technology's immaturity has the most impact, the high investment cost is the most impressive risk, and privacy has a critical role in risks relationships. In addition, the high investment cost has the highest priority among other risks and the privacy and issues with contract law are ranked second and third, respectively. [ABSTRACT FROM AUTHOR]