The Mediterranean Basin biodiversity hotspot is known to be one of the most biologically rich and complex regions on Earth. The north-western part of the hotspot (the area that covers all of the Iberian Peninsula, southern France, most of Italy and Malta) supports important river, lake, karst and wetland systems critical for the survival of threatened and restricted range freshwater species. Within the north-western Mediterranean region of the hotspot, freshwater Key Biodiversity Areas (i.e., sites of importance for the global persistence of biodiversity) have been identified. The purpose of this report is to help guide and inform policies and conservation actions for freshwater biodiversity in the region.