In 2010, the Convention on Biological Diversity adopted the Strategic Plan for Biodiversity 2011-2020. As international attention turns to the development of the post-2020 Global Biodiversity Framework, discussions are focusing on the way in which other effective area-based conservation measures (OECMs) should be reflected in the Framework. To inform this discussion, we gathered in-depth perspectives and expert elicitation on the opportunities and challenges that OECMs offer and present to biodiversity conservation. To do so, we conducted semi-structured interviews with experts involved in OECM-related deliberations. The explicit consideration of OECMs in conservation policy represents a recognition that there are sites outside of formal protected area networks that benefit biodiversity and ecosystems in important ways. However, these benefits and the future social and ecological impacts of OECMs will depend largely on robust guidelines for their identification, effective monitoring, and whether relevant actors report the areas they govern as OECMs.