The research addresses the "Legal Challenges in the Regulation of Cryptocurrencies under the Brazilian Constitution", with the objective of analyzing the legal difficulties related to the regulation of cryptocurrencies in the country. In addition, it seeks to investigate how these digital currencies align with constitutional principles, examine their impact on the Brazilian economy and the security of the business environment, and propose recommendations for adequate regulation. The research problem can be summarized in the following question: In what way does the regulation of cryptocurrencies, in light of the Brazilian Constitution, influence the individual guarantees of citizens and the legal security of the system? The regulation of cryptocurrencies in Brazil presents significant challenges in the legal and constitutional context. Although these virtual currencies play a growing role in the global economy, their decentralized nature, lack of state control, and volatility generate uncertainties that directly affect the Brazilian legal system. The research uses a bibliographical approach, based on academic studies, doctrines, and legislation, aiming to offer a critical view on the subject and contribute to the legal debate around cryptocurrencies in the national scenario.