A total of 12 gnat species are reported for the first time from Finland (3 Cecidomyiidae, 1 Keroplatidae, 8 Mycetophilidae), and the occurrence of Macroceranigropicea Lundström in Finland is verified. All material was collected from the Finnish Lapland, mainly from the north boreal ecoregion. Two of the recorded species are likely to be pyrophilous, associated with forest fire sites. A photo of the ventral appendage of the gonocoxite of Brevicornusetigerum Zaitzev is provided for the first time. The male hypopygium of Mycetophilaharuspica Plassmann is redescribed.
Keywords: Cecidomyiidae; Keroplatidae; Lestremiinae; Mycetophilidae; Porricondylinae; fungus gnats; gall migdes.