This paper surveys public participation policies across a range of international institutions and environmental agreements to better understand whether opportunities exist for meaningful participation in international decisions that affect the environment. It examines the implementation of Principle 10 in the Rio Declaration, supported by the Aarhus convention which details measures countries must take to ensure that citizens have access to information, participation, and justice in decisions that affect the environment. It looks specifically on how Multilateral Development Banks, Multilateral Environmental Agreements, and trade regimes and regional economic bodies have lived up to these goals. Co-produced by WRIÆs (World Resources Institute) International Financial Flows and the Environment Program (IFFE) and The Access Initiative (TAI), the survey concludes that: Policies on public participation are quickly becoming the norm; Public participation at the national level is uniformly weak; domestic stakeholders have limited ability to influence international decisions that affect their environment; Institutions and agreements subject to the greatest public scrutiny have the most advanced public participation policy frameworks; A common methodology is needed to assess the implementation and practice of public participation. This analysis provides the reader with an overview of where multilateral institutions are contributing to the development of effective public participation, and the extent to which opportunities exist in domestic and international political spheres for affected parties and the interested public to incorporate sustainability concerns in multilateral decision-making processes.