This policy brief summarizes recent developments in regional and global mutual accountability mechanisms for development cooperation since 2010. It finds that mechanisms now utilize more balanced data sources, better represent different development actors, provide sufficiently frequent assessments, and are increasing efforts to engage civil society. However, challenges remain to consolidate the landscape of mechanisms, produce more evidence for decision-making, enhance relevance of assessments, and facilitate stakeholder engagement. The brief recommends undertaking a mapping of mechanisms, facilitating research on accountability and evidence, making better use of data, and assessing capacity needs to strengthen dialogue on development cooperation.