The genus Schizomyia Kieffer (Diptera: Cecidomyiidae) is newly recorded in Taiwan and Schizomyia maesae Elsayed, Lin & Tokuda n. sp. that forms irregular galls on stems of Maesa perlaria (Lour.) Merr. var. formosana (Primulaceae) is described as new to science. A description of larva, pupa and adults, illustrations and ecological features of the new species are given.