The first Red List assessment of lichenized fungi reported from Bulgaria is presented. The IUCN Red List criteria were applied to 138 species to assess their current extinction risk and to highlight the main threats for them. Our results revealed that six species are Regionally Extinct (RE), 23 species are Critically Endangered (CR), 20 species are Endangered (EN), 13 species are Vulnerable (VU), 11 species are Near Threatened (NT), 58 species are Least Concern (LC), and seven species are Data Deficient (DD). The most important floristic regions for lichen conservation are the Pirin Mts (26 species), the Balkan Range (25), the Rila Mts (25), the Rhodopes (20), Mt. Vitosha (16), Mt. Strandzha (16), and the Black Sea coast (15). The main threats are development of tourism and recreation activities that destroy habitats (60 species affected), air pollution (55), climate change (53), development of tourism and recreation areas (41), harvesting trees and other woody vegetation (unintentional effects) (27), ecosystem modifications that convert or degrade habitats (18), and development of housing and urban areas (14). The information provided in this Red List will assist to further develop the national conservation strategy for Bulgaria. Keywords: biodiversity, Bulgaria, conservation status, fungal diversity, IUCN Red List categories, lichens, red listing, Regionally Extinct (RE), threatened species.