Studies of institutional translation have traditionally focused on European Union (EU) institutions and legislative genres. In order to develop a more comprehensive characterization of translation at international organizations beyond EU supranational law, this study compares a full mapping of multilingual text production at EU institutions to that of two representative intergovernmental organizations (IGOs), the United Nations (UN) and the World Trade Organization (WTO), over three years (2005, 2010, and 2015) in three common official languages (English, French, and Spanish). The corpus-driven quantitative analysis and categorization of all texts from a legal-functional perspective corroborate the interconnection of a wide range of textual genres that perform, support, or derive from central law-making, monitoring, and adjudicative functions, or fulfill other administrative purposes. The findings also highlight interinstitutional variation that reflects the features of each legal order, in particular the prominence of hard law-making at the EU (with a high proportion of drafts and input documents) as opposed to larger translation volumes in monitoring procedures at the UN and the WTO. This mapping is considered instrumental to further analyze legal and other specialized translation practices in international institutional settings, and ultimately to inform translator training and translation quality management.