All Oriental and Australasian/Oceanic species of Pegadomyia are re-examined. A detailed study of the generic characters shows that Pegadomyia actually contains two easily diagnosed genera: Pegadomyia Kertész, 1916 and Pseudopegadomyia gen. n. Pegadomyia now includes the type species P. pruinosa Kertész, 1916 (occurring in Malaysia, Taiwan and Thailand) and three new species: P. ceylonica sp.n. (from Sri Lanka), P. nana sp.n. (from Laos) and P. nasuta sp.n. (from Malaysia). Pseudopegadomyia contains Ps. jamesi sp.n. (based on a type series from the Philippines) and two species originally belonging to Pegadomyia: Ps. glabra (Bezzi, 1928), comb.n. (Fiji Is.) and Ps. nuda (James, 1948), comb.n. (Australasian Region and Philippine Is.). Figures of the diagnostic characters of all treated species are included. Identification keys and a map showing the distribution of all species of both genera are presented.