This report provides a new up-to-date review to identify conservation priorities and a new Red List for the 576 butterfly species known to occur in Europe. The geographical scope is continentwide, and covers all countries within the Council of Europe, including the Azores, Madeira, the Canary Islands, Russia east to the Ural mountains and the whole of Turkey. Data were collected through a network of over 50 expert national compilers and threat status was assessed using the new lUCN criteria, especially adapted for use at a Continental level and with data available for butterflies. The analysis showed that a total of 69 species are threatened in Europe (12% of the total) either because of their extreme rarity or rapid decline. They comprise 17 threatened globally and 52 threatened at a European level. A further 43 species are classified as Lower Risk (near threatened). Criteria are developed to identify Species of European Conservation Concern and the threats and distribution of threatened species are described. The overall conclusion is that many European butterflies are under serious threat, especially from rapidly changing land use and the intensification of agriculture and forestry. A major new initiative for conserving European butterflies is therefore needed. A series of recommendations are given including the need for policy changes; better protection and management of key butterfly habitats; identification of prime butterfly areas; further research, survey and monitoring; the addition of the 34 most threatened species to the Bern Convention and EC Habitats and Species Directive; and an overall action programme for European butterflies.