Comprehensive overview of participatory approaches to monitoring, focusing on community monitoring of environmental changes and natural resource management interventions. The Working Paper draws on an extensive review of published literature and interviews with practitioners with experience in participatory monitoring. Ten case studies are presented and comparatively analysed and discussed. The paper begins by providing a general overview of conventional monitoring and then discusses the basis of participatory monitoring approaches, especially their impacts and benefits, how participation is achieved, and how indicators are perceived and developed. Trade-offs in meeting diverse, often conflicting needs and objectives, particularly between the need for scientific rigour on the one hand, and enhanced participation in participatory monitoring process on the other. The last section of the paper presents and compares three different categories of approaches to participatory monitoring which have been successful at achieving community involvement. These approaches are methodologies that are developed from the use of PRA, those that use oral testimony, and those that adapt scientific approaches to ecological assessment. Finally, current gaps in our understanding of participatory environmental monitoring are identified. The review finds that further documentation is required of the negotiations that occur within and between stakeholder groups, particularly in terms of identifying and establishing different priorities and objectives. It further suggests that few approaches to monitoring involve all stakeholders in the complete monitoring process, which takes longer to establish and implement. The review highlights that the monitoring process must provide real and meaningful benefits for all stakeholders, especially for local people whose long term participation is central to the monitoring process.