The current loss of biological and cultural diversity is a well-acknowledged phenomenon. According to most projections, 20 percent of the world's species may cease to exist over the next 30 years. Less widely known, though attracting increasing attention, is the loss of traditional knowledge about the environment, the ways in which humans relate to the latter and how it can contribute to global sustainability. Many authors have remarked that the overlap between biological and cultural diversity is not random and that the loss of cultural and biological diversity is tightly linked. Mediterranean landscapes are a particularly intense mosaic of species and cultures. These landscapes constitute one of the world's hotspots of biocultural diversity, which is nevertheless eroding quicker than in most parts of the world, while it is generally less studied than in other regions like in the tropics. Because of this relative void and the region's uniquely rich history, a first special issue to analyze its biocultural diversity and assess its current threats and dynamics seems needed, addressing both continental and marine ecosystems, including small islands.