A total of 317 species of Mycetophilidae are recorded from the Gemer region in central Slovakia. The material was obtained mainly in the years 2008-2011 by means of Malaise traps and by individual collecting by the authors. A new species of Mycetophila Meigen, M. gemerensis sp. n., is described and additional 47 species are recorded as new to Slovakia. A new synonym is proposed: Mycetophila quadra Lundström, 1909 = M. chamberlini (Laffoon, 1957) syn. n.