The purpose of this guidance manual is to show how the value of ecosystem services can be estimated and incorporated into decision making. Specifically, it is designed to help a broad audience of conservation managers, government officials, private sector managers, NGOs, and statisticians to understand the available information on the values of ecosystem services and how this information can be transferred to inform the decisions that they make. It explains why you would undertake a study, who should be involved, how to implement the study and how to use the results. The development of this guidance manual was funded by the United Nations Environment Programme.