The wild bees Andrena assimilis Radoszkowski, 1876, and Andrena gallica Schmiedeknecht, 1883, are morphologically very similar species and by some authors they are treated as one taxon – A. assimilis. Some other authors treat A. gallica as a subspecies of A. assimilis, others assert that both A. gallica and A. assimilis are valid species. After analysing the morphological features, we confirm that they should be treated as two distinct species. The following characters help to separate A. gallica from A. assimilis: in the case of females – the colouration of the stigma and veins in the forewing, in the case of males – the microsculpture of the surface of the metasomal terga, the punctation of terga II–III, and the width of the edeagus. Andrena gallica was reported in Poland in the first half of the twentieth century from the following regions: Baltic Coast, Kraków-Wieluń Upland, Małopolska Upland, and Wielkopolska-Kujawy Lowland. Due to the synonymy, these records were included in the distribution of A. assimilis. After more than 50 years, the occurrence of A. gallica in Poland has been confirmed. The new record of the species is reported based on the specimen collected in Kampinos National Park (Mazovian Lowland). In 2004, one male was collected on fallow land. Water pan-traps (Moericke traps) were used to do the collecting. Diagnoses of both species, data on their biology, as well as distribution, are provided.