Thirty eight species are recognized in the Neotropical Region. Twenty four are redescribed and illustrated and fourteen were not redescribed, because they are well definite in the original description. A new combination for Mydaea triseta Curran, 1931 to Phaonia and the revalidation of P. nigripuncta Stein, 1911 are made. Five new synonyms are proposed: P. coquilletii (Vimmer, 1939) = P. punctinervis Stein, 1911; P. nigrocincta Stein, 1918 = P. abdita (Giglio-Tos, 1893); P. praedatoria (Snyder, 1957) = P. latinervis (Stein, 1904); P. vulgata (Albuquerque & Medeiros, 1980) = P. similata (Albuquerque, 1957); P. nigra (Albuquerque & Medeiros, 1980) = P. trispila (Bigot, 1885). A key to the neotropical species is presented for the thirty eight recognized species.

Phaonia boliviana sp.n., Phaonia equatorialis sp.n., Phaonia punoensis sp.n., Phaonia quercus sp.n. and Phaonia soratiensis sp.n. from Neotropical Region are described and illustrated.

A study comparing the morphology of the proboscis of the following muscoid species is presented: Scatophaga stercoraria (Linnaeus, 1758) (Scatophagidae), Fannia canicularis (Linnaeus, 1761) (Fanniidae), Taenomyia auricollis Stein, 1918 (Anthomyiidae) and Phaonia valida (Harris, 1780) (Muscidae). Comparisons were made with Archiborborus sp. (Acalyptratae, Sphaeroceridae), Calliphora vicina Robineau-Desvoidy, 1830 (Oestroidea, Calliphoridae) and other muscids.

Bigotomyia californiensis Malloch, 1923 and B. houghii (Stein, 1898) are transferred to Phaonia, redescribed and illustrated. A lectotype is designated for the former.