The subfamily Midilinae Munroe, 1958b, is revised for the first time as a discrete and coherent group, though Hampson (1895) associated three genera and five species as part of his subfamily Schoenobiinae. Seven genera, 45 species, and six additional subspecies are recognized in the present study, of which the following one genus, 27 species, and five subspecies are described as new: Hositea punctigera, Brazil and Peru; H. regina, Brazil; H. cyanops, Surinam, Brazil and Bolivia; Cacographis osteolalis azteca, Mexico and Central America; C. o. inca, Peru; C. o. sara, Bolivia; C. macrops, Bolivia; Dismidila hermosa, Mexico; D. regularis, Colombia; D. similis, Bolivia; D. obscura, Brazil; D. pallida, French Guiana; D. gnoma, Guatemala; D. drepanoides, Peru; Midila lamia, Brazil and Guianas; M. larua, Venezuela; M. quadrifenestrata subfuscifusa, Guianas; M. thessala, Bolivia, Brazil; M. strix, Peru; M. daphne minor, Gorgona I., Colombia; M. agrippina, Bolivia, Peru; M. poppaea, Guianas, Colombia, Peru; M. crenulimargo, Peru; M. latipennis, Ecuador; M. discolor, Ecuador; M. sympatrica, Guatemala; M. fonteboalis, Brazil, Peru; M. centralis, Guatemala; M. soror, Panama; M. guianensis, Guianas; M. equatorialis, Ecuador; Pastranaia, type-species Hygrochroa fenestrata Ménétriés; P. tumidifrons, Brazil, Guianas, Colombia. Phryganomima Hampson is transferred to Midilinae from Pyralinae. Midila attacalis Walker is raised to a subspecies of M. quadrifenestrata (Herrich-Schäffer) and M. orfilai Pastrana is sunk as a synonym of M. g. attacalis. Tetraphana lilacina Pagenstecher is transferred from Midila to Pastranaia and Midila martinezi Pastrana and M. lilacina Whalley are sunk as synonyms of it.