Analysis and engagement with partners working on ecosystem services transactions, policies and laws over the past 10 years have demonstrated a clear need to better understand the legal and institutional frameworks that have the potential to promote or hinder the development of payments for ecosystem services (PES) schemes, as well as the complex legal considerations that affect ecosystem services projects. In response, the IUCN Environmental Law Centre and The Katoomba Group have worked on a joint initiative to analyze the legal and institutional frameworks of water-related PES schemes and projects in four Andean countries: Brazil, Bolivia, Colombia and Peru.