A biodiversity baseline study is the work done to collect and interpret information on the biodiversity values occurring at a site, their current condition, and trends before a project commences. The biodiversity baseline study plays important roles in supporting the assessment of impacts and risks of a project, applying the biodiversity mitigation hierarchy, and designing the long-term biodiversity monitoring program (if one is required). Biodiversity risks, management requirements, and information needs will vary according to the project, and therefore the biodiversity baseline study should be proportional and specific to the anticipated risk and significance of impacts from the project. This Quick Guide section of the report provides a summary of the important "good practices" for biodiversity baseline studies that support biodiversity-inclusive impact assessment and management planning in environmental and social impact assessments (ESIAs).