[in Slovak with English abstract: ] Lichen-flora of National Park Muránska planina (Veporské vrchy Mts, Stolické vrchy Mts, Spišsko-gemerský kras karst; Central Slovakia) has been investigated since 1995. An overview of its diversity within the Hrdzavá dolina valley is presented here. In the course of 6 excursions 191 species were recorded; 72 of them (38%) belong to the Red list of Slovak lichens. Out of those considered extinct 4 were recorded – Arthothelium ruanum, Collema conglomeratum, Gyalecta truncigena and Strangospora ochrophora (the last one incorrectly reported in Slovakia). 16 species were not treated in the latest checklist of Slovak lichens (Pišút et al. 1999) – Absconditella sphagnorum, Agonimia allobata, Arthonia helvola, Bacidia igniarii, Caloplaca obscurella, Catillaria alba, Collema occultatum, Lecania cyrtellina, Lepraria flavescens, L. lesdainii, Micarea hedlundii, Multiclavula mucida, Pertusaria constricta, Psoroglaena stigonemoides, Scoliciosporum curvatum and Verrucaria viridigrana. All the species listed above, apart from as well as Dirina stenhammari, Squamarina lamarckii and Thelopsis lojkana are commented. Protection of the whole of the Hrdzavá dolina valley is proposed.