This manual is intended to support adaptive decision-making in vulnerable communities. The participatory monitoring, evaluation, reflection and learning (PMERL) framework presents a participatory methodology for developing and monitoring against community-based adaptation (CBA) indicators. The manual recommends three types of information which are essential to monitoring and evaluating CBA: practice, outcomes and context. These three types of information are needed, because practitioners need to know: what is being done and whether it is being done in ways that engage and support the most vulnerable communities (practice); if activities are resulting in actual vulnerability reductions on the ground (outcomes); and if vulnerability reductions are occurring in light of changing climate and other contexts, to better understand how climate and other stresses influence outcomes and to ensure outcomes are sustainable under climate and other stresses.