Beginning in the mid-1970s, the UN General Assembly conducted a review of the multilateral treaty-making process. A 1980 Report of the Secretary-General on this review concluded that there was “extensive diversity” among the various procedures that had been utilized in treaty-making processes, including whether such processes made use of established entities or were ad hoc in nature, the extent to which this involved expert or representative bodies, and the extent of the involvement of the General Assembly. The only generalization that was seen to be possible was that such processes almost always involved a multistage process. This chapter assesses the conclusions of the Secretary-General’s 1980 Report in light of the practice of the intervening years, focusing, in particular, on the role of the Secretariat in the treaty-making process, and adopting for the purposes of its analysis the five stages in the multilateral treaty-making process as identified in the Secretary-General’s 1980 Report: initiation of treaty-making, formulation of multilateral treaties, adoption of multilateral treaties, post-adoption concerns, and supplementing and updating treaties. This chapter also briefly discusses other treaty-making activities of the Secretariat.