The Yearbook of Legal Practices and International Organizations (YLPIO) is an annual legal publication examining the legal practices, laws and conventions that both govern and enable all international organizations. This inaugural volume is introduced by an editorial exploration of the contemporary law of cooperation between international organizations and Member States–recognising that the effectiveness of the former depends significantly on the support of the latter. The Articles section convenes authoritative and practically significant analyses of the governance role of international administrative tribunals, formal amendment to the treaty-basis of the Bretton Woods Institutions, the institutional architecture of the hundred-billion-dollar trust funds administered by the World Bank and International Monetary Fund (IMF), and the evolving organizational response at the United Nations to sexual misconduct. The Materials section features a position paper proposing a new approach to the privileges and immunities of international organizations based on ‘conditional immunity’, together with a practitioner manual identifying the extensive employer duties of international organizations constituted by the jurisprudence of the International Labour Organization Administrative Tribunal. This volume concludes with the YLPIO Interview, sharing the professional expertise and organizational vision of Rhoda Weeks-Brown, the pioneering former General Counsel of the IMF.