The process of establishing a biosphere reserve (BR) under UNESCO’s Man and Biosphere (MAB) programme on the island of Samothraki in the NE Aegean (Greece) is conceptualized as a case study of transdisciplinarity. The point of departure has been the wish to preserve an island with unique natural and cultural heritage from potentialy destructive pathways of transforming it into just another Greek beach tourist destination and to come up with an alternative development model. This has generated a unique opportunity to pre-structure, observe and reflect on a process of evolving decision making and management towards a sustainability transformation of an island. After several years of research and communication efforts, the mayor of Samothraki, with the unanimous support of the municipal council and the Greek National MAB Committee, submitted an application to UNESCO for Samothraki to be included in the World Network of Biosphere Reserves. A positive decision will make Samothraki the first post-Seville BR in Greece. After briefly introducing the study area, this report will discuss the opportunities of this new perspective, as well as the challenges that need to be faced, both on the ground and in people’s minds, for the island of Samothraki to become a true model of sustainable development in the wider region.