The Alps are the most intensively exploited mountains in the world. And yet they still represent Europe’s largest pool of biodiversity, inextricably linked to the quality of life of its inhabitants and visitors, present and future. WWF, in collaboration with ALPARC (Alpine Network of Protected Areas), CIPRA (International Commission for the Protection of the Alps), and ISCAR (International Scientific Committee on Research in the Alps) launched an initiative to determine the Alpine regions which need to be given priority for conservation based on biodiversity values. These regions were identified in the course of a two-year process, culminating in two international workshops with scientists, representatives from NGOs, and institutions. The first workshop was held in May 2002 in Gap, France and the second in September 2002 in Alpbach, Austria. The results of this process, which are published in this booklet, contribute to a better understanding of biodiversity in the Alps and provide a guide to the areas in which priority conservation actions should be undertaken.