This presentation considers the origins of the International Nuclear Information System (INIS), an indexing and abstracting database put into operation by the International Atomic Energy Agency in 1970. The history of INIS and its immediate predecessor databases in the IAEA underline the degree to which the Agency serves as an technoscientific information management organization. This aspect of the IAEA’s wider international mission is underrepresented in the historical literature but significant if we consider such information management as a matter of technodiplomacy, in which negotiation and technical development of information infrastructures involve co-constructed, contingent processes. We find with INIS that technology contextualized and structured diplomatic action, while simultaneously diplomacy facilitated and shaped an information infrastructure. This had implications not only for the IAEA and the global nuclear order but for the treatment of science and technology in the United Nations system