This chapter navigates between technological and social determinism in highlighting the mutually constitutive relationships between blockchains and global anti-money-laundering governance. It reveals how the technical features of blockchain technologies shape and constrain governance in the international anti-money-laundering regime. The chapter illustrates how the responses of this regime in turn shape and constrain the evolution of this set of emergent technologies. It illustrates the mutual constitution of technology and global governance through an examination of relationships between blockchain technologies and the international anti-money-laundering (AML) regime. Money laundering, simply put, is the ‘mainstreaming’ of proceeds from illicit activities into the legitimate financial system in ways that conceal their illegitimate origins. Two specific features of blockchain technologies pose novel implications for international money laundering: the decentralisation and quasi-anonymity of transactions on global networks. The chapter illustrates an underappreciated element of global governance: the mutual constitution of international regimes and emergent technologies.