This paper is the third of the Adaptation Briefing series under the NDC Support Cluster, which aims to provide concise and easy to digest information on key topics, relevant for projects working on climate change adaptation. The Briefings – besides short thematic introductions – offer well-selected references, which provide a rich source of further knowledge and information on practical solutions and can help projects navigate adaptation processes in their respective countries. This briefing guides its reader through the complex subject of Monitoring, Evaluation and Learning (MEL) of Adaptation. It gives an overview about the benefits of investing in MEL and provides current challenges. It explains what you need to know about the debate on M&E and transparency under the Paris Agreement and Katowice and offers a rich list of further literature and practical solutions.