First records of twenty-three gall midge species in Denmark are reported: Asphondylia ervi Rübsaamen, Contarinia acetosellae Rübsaamen, C. viburnorum Kieffer, Dasineura astragalorum (Kieffer), D. fructum (Rübsaamen), D. harrisoni (Bagnall), D. lotharingiae (Kieffer), D. papaveris (Winnertz), D. saxifragae (Kieffer), D. traili (Kieffer), Herbomyia robusta Möhn, Jaapiella chelidonii Fedotova, Lasioptera arundinis Schiner, L. calamagrostidis Rübsaamen, Mayetiola festucae Ertel, M. phalaris Barnes, M. ventricola (Rübsaamen), Mycodiplosis coniophaga (Winnertz), Parallelodiplosis galliperda (Löw), Piceacecis abietiperda (Henschel), Rabdophaga strobilina (Bremi), Taxomyia taxi (Inchbald) and a probably undescribed species of Contarinia Rondani. Thus, 363 fully identified gall midge species are now documented from Denmark along with 25 species, which have been identified to genus level only. The species number per subfamily is 335 Cecidomyiinae (311 fully identified and 24 identified to the genus level only), 0 Winnertziinae and 14 Porricondyliinae (13 fully identified and one identified to the genus level only), 24 Micromyinae and 15 Lestremiinae.