The emergence of decentralized cryptocurrencies has introduced significant legal and jurisprudential challenges regarding their nature, ownership, and transactions. A key issue is their potential conflict with the Islamic principle of "I'anah Bar Ethem" (aiding in sin), which prohibits facilitating sinful acts. Cryptocurrencies, operating outside government oversight, can enable crimes like money laundering and terrorist financing, potentially qualifying as aiding in sin. This necessitates an examination of whether this principle applies to decentralized cryptocurrencies from the perspective of Imami jurisprudence. This research aims to explore the impact of the "I'anah Bar Ethem" principle on decentralized cryptocurrencies within Imami jurisprudence. Given the novelty of cryptocurrencies and the absence of comprehensive legal frameworks, understanding the relevant Islamic legal rulings is crucial. Such analysis can aid in creating a robust legislative and judicial framework for regulating this domain.Adopting a descriptive-analytical approach, the study examines the nature of decentralized cryptocurrencies, the concept of "I'anah Bar Ethem" in Imami jurisprudence, and the interplay between these two. Findings reveal that decentralized cryptocurrencies, by bypassing governmental control and facilitating criminal activities, fall under the prohibitions outlined in the "I'anah Bar Ethem" principle. This underscores the need for legal and regulatory mechanisms to manage and monitor these technologies effectively, ensuring their benefits are harnessed while preventing misuse.