Conferences of the Parties (COPs) are intergovernmental meetings established by treaties to review and promote the implementation of their provisions. The literature on COPs is limited and almost exclusively based on multilateral environmental agreements. The article departs from this scholarship to show that COPs are now present in different areas of international law and to discuss some of the ways in which these bodies influence the conventions that establish them. In particular, it considers how COPs affect the content and the implementation of their parent treaties. The article focuses on the bodies established by four treaties selected as case studies: the WHO Framework Convention on Tobacco Control; the Convention for the Protection and Promotion of the Diversity of Cultural Expressions; the Convention on Cluster Munitions; and the United Nations Convention against Corruption. Based on the examination of the normative decisions adopted by these organs, the article argues that COPs’ activities (i) specify and develop the content of their parent treaties by setting procedural and substantive standards that states parties must meet to comply with their obligations; and (ii) support the implementation of their parent treaties by seeking to strengthen their social and political position, facilitating the adoption of measures by states parties. COPs pursue this second goal by building momentum in favour of the implementation of their treaties, stigmatizing their adversaries, and connecting their conventions with established international legal narratives.