We present the taxonomic revision of genera Dennstaedtia, Microlepia, and Mucura (Dennstaedtiaceae: Dennstaedtioideae) for Brazil. Ten species are recognized: D. aculeata (recently described), D. cicutaria, D. concinna (rescued from synonymy), D. cornuta (with a new circumscription), D. fluminensis (rescued from synonymy), D. obtusifolia (with a new circumscription), Micr. speluncae (naturalized), Muc. dissecta, comb. nov. (rescued from synonymy), Muc. tamandarei, comb. nov. (rescued from synonymy), and Muc. tenera, comb. nov. (rescued from synonymy). Excluded from Brazil are three commonly applied names: D. dissecta, Muc. bipinnata (= D. bipinnata), and Muc. globulifera (= D. globulifera). We present keys to genera and species, comprehensive descriptions, illustrations, maps of distribution, and type data for all species (including the designation of 10 lectotypes).