This article explores the ‘practice’ of the International Monetary Fund (‘imf’) by focusing on the organization’s approach to recognition of governments. After analysing this approach in some detail, it surveys the organization’s practice from three perspectives. First, it identifies the different functions of practice within the imf’s legal system, including the imf’s treaty. Second, the article reviews how the practice of the imf relates to key conceptions of practice under international law: (i) as part of international custom; (ii) under articles 31(3)(b) and 32 of the 1969 Vienna Convention on the Law of Treaties; and (iii) as a ‘rule of the organization’. Finally, the article compares ‘practice’ under the imf treaty and a national legal system by considering how the United States’ Supreme Court has interpreted the power to recognise governments under the USConstitution.