Recent research illustrates the essential role that biodiversity plays in both ecosystem functioning and the provisioning of ecosystem services for human well-being. Despite the acknowledged necessity to include the social and economic dimensions into biodiversity conservation research, integrative approaches based on ecosystem services assessment have scarcely been used. This might be in part because ecosystem services have usually been approached from traditionally separated disciplines in the absence of a shared theoretical framework. This chapter is intended to develop such a comprehensive conceptual framework for incorporating ecosystem services assessment into biological conservation research. In doing so, we first reviewed the different existing approaches to ecosystem services assessment, looking for unifying concepts in order to provide an integrative framework. Our proposal focuses on the service-providing functions as the key element to tackle the relationships among society, ecosystems and biodiversity. In addition, an interdisciplinary approach is proposed for the valuation of ecosystem services provided by biodiversity, which integrates the ecological, sociocultural and economic values of biodiversity. Finally, we reflect on the research needs for evaluating the ecosystem services provided by biodiversity and their relationship with biological conservation.