The link between biodiversity and ecosystem services is obvious. However, due to the complexity of both terms, discussions are often narrowed to specific components, provoking many useless debates. Because ecosystem service assessments are intended to provide guidance for ecosystem management, the confusion over how to treat biodiversity is potentially a serious problem. A clarification of the biodiversity concept in relation to ecosystem services is needed. This chapter sketches the history of both terms and gives an overview of the established functional linkages between them. Conclusively, when a broad multitude of values is taken into account, ecosystem services are an opportunity rather than a threat to biodiversity conservation. The evidence base for protection of our natural capital is weak, and being explicit about societal values of biodiversity is essential. Debates should focus on the consequences of biodiversity decline for service delivery and on incorporating physical limits in natural resource management.