This database contains documented observations of the relationship between biodiversity and ecosystem functioning in urban areas globally published between 2006 and June 2023. We systematically reviewed publications from Web of Science. To be included, studies needed to explicitly assess how at least one metric of biodiversity related to at least one ecosystem function and must have been conducted in an urban setting (as defined by the study author). We only included studies that explicitly assessed correlations between biodiversity and ecosystem functioning or tested cause/effect models or experiments. We extracted data related to basic study information and methodology, and the ecosystem function assessed, focal taxonomic group, biodiversity metric, and direction of the biodiversity-ecosystem function relationship.