Two new species of Drosophilidae from Uruguay are described and illustrated: Drosophila montevidensis sp. nov. (Holotype male in MZSP: Facultad de Agronomía, Universidad de la República, Montevideo city, Department of Montevideo), and Scaptomyza pipinna sp. nov. (Holotype male in MZSP: Sarandí del Consejo, near north shore of Laguna de Castillos, Department of Rocha). The former species belongs to the D. tripunctata group and is sibling to Drosophila nappae Vilela, Valente & Basso-da-Silva, 2004, differing mainly in characters of the aedeagus. The latter is closely related to Scaptomyza striaticeps Wheeler & Takada, 1966, from which it can be distinguished by color and terminalia characters. The new Drosophila species was successfully cultured in a modified banana-agar medium which is provided. Photomicrographs of mitotic and meiotic chromosomes of D. montevidensis sp. nov. are also included.