The biological diversity of forest ecosystems has received increased attention during the last decades, and today there is a broad consensus that protecting forest biodiversity is an important aspect of sustainable forest management. The use of indicators makes it possible to present an overview of this subject and to assess the current situation in relation to political as well as operational management goals. This report presents the results of a compilation of national forest inventory data from Finland, Norway and Sweden collected during the 1990s. A methodology for harmonising data indicators has been developed, and the resulting indicators are grouped under the following seven themes: forest area and land cover, resource management, forestry methods and land use, forest dynamics, forest states, species diversity and threatened species, and conservation measures.