A floristic survey was carried out in 42 localities of the Eastern Italian Alps. The Dolomites were explored in more detail, especially in protected areas. The main habitats were: 1) dolomitic and siliceous boulders and outcrops in the alpine/subalpine belts; 2) natural grasslands, both on calcareous and siliceous substrata in the alpine belt; 3) subalpine and montane forests dominated by conifers; 4) siliceous freshwater habitats in the alpine belt; 5) man-made substrates in the montane belt. 182 lichens and 6 lichenicolous fungi are reported. Twelve lichen species are new to Italy: Absconditella lignicola, Caloplaca soralifera, Cheiromycina flabelliformis, Ionaspis obtecta, Lecanora exspersa, Micarea hedlundii, M. micrococca, Mycobilimbia aff. olivacea, Normandina acroglypta, Placynthiella dasaea, Psoroma tenue and Stereocaulon coniophyllum. 18 species are new to the Veneto Region and 9 species are new to the Trentino-Alto Adige Region. An additional 45 species are new to the Paneveggio-Pale di San Martino Natural Park. Among the surveyed habitats, forests and freshwaters are worthy of further research as well as of conservation, since several rare species were found.