Conservation and sustainable use of biodiversity, ecosystems and their services are key principles behind the establishment of “Biosphere Reserves”. Mapping of ecosystem services is one of the activities that is expected to increase the knowledge of sustainable land use planning. The Biosphere Reserves, established by the UNESCO Man and Biosphere Programme, aims to find the balance between nature conservation, use of natural resources, recreation and other culture-related activities. For this purpose, the ecosystem services approach is a promising tool for examining the relationships between people and nature in practice. This study applies the ecosystem services approach and examines which ecosystem services are perceived to be relevant in the North Karelia Biosphere Reserve in Eastern Finland. The results of a matrix method, with expert-based approach, showed that particularly old-growth forests and undrained open and forested mires have a broader potential to provide different ecosystem services. Water and urban areas are considered important for cultural services. However, these areas cover only a relatively small area altogether. The results of the ecosystem services assessment were compared to areas of high biodiversity, as defined by local biodiversity experts. The areas with high capacity for ecosystem services provision (from now on “high ecosystem services areas”) were found in areas with high biodiversity. In most cases, these areas are already under protection. The results also showed that ambiguity is an issue with the use of the ecosystem services concept in both stakeholder and expert evaluations.