The Mediterranean Basin (MB), connected by cultural exchanges since prehistoric times, provides an outstanding framework to study species introductions, notably in mammals. Carnivores are among the most successful mammalian invaders. As such, a number of middle-sized representatives (“mesocarnivores”) such as the domestic cat and mongooses have been pinpointed for their deleterious impact on the native fauna. In the MB, three species of mongooses (Herpestidae) and one genet (Viverridae) are or have recently been recorded and none of them has been considered native: the Indian grey mongoose Herpestes edwardsii, the small Indian mongoose H. auropunctatus, the Egyptian mongoose H. ichneumon, and the common genet Genetta genetta. In order to clarify the history of introduction and status of the mongooses and genet in Europe, I review various bodies of evidence including (1) their natural history and relationships with humans in their native ranges, (2) their history of introduction in Europe, (3) the enlightenments—and sometimes contradictions—brought by recent genetic analyses on their dispersal histories, and (4) their range dynamics and ecological interactions with the European fauna. The species of herpestids and viverrids present in Europe fall into three categories: (1) introduced and spreading ( G. genetta, H. auropunctatus), (2) introduced and extinct ( H. edwardsii), and (3) natural disperser and spreading ( H. ichneumon). In view of the reviewed evidence, there is weak support for a deleterious impact of the mongooses and genet on the European fauna (except possibly on the herpetofauna of small Adriatic islands in the case of H. auropunctatus), notably in comparison with genuine invasive species such as the black rat and the domestic cat. Rather than inefficient control programs such as those targeting H. ichneumon in Portugal and H. auropunctatus in Croatia, we suggest that a greater attention is focused on the restoration of large Carnivores (the natural regulators of mesocarnivore populations), mesocarnivore communities and natural habitats, to contribute to a more sustainable way of “managing” the mongooses and genet in Europe.