Large native geographical range and number of introduction events are often invoked to explain the successful establishment of alien mammal species. To infer the native geographic range of the Siberian chipmunks Tamias (Eutamias) sibiricus (Lax.) invasion in France, we identified the subspecies that individuals sampled in 5 out of the 11 established populations belonged. Based on craniometrical measures, variation in the mtDNA sequence of the cytochrome b, and alarm call sonogram shape, all French specimens were members of T. (E.) s. barberi which has the smallest geographical range (Korean peninsula) of the three recognized subspecies. An intense pet trade between European countries and Korea until the 1980’s best explains the success in establishment of this small ground-squirrel in France, where it was released mainly by private owners. Size of the native geographical range should be interpreted with caution in explaining the establishment of an invasive species, at least without a precise knowledge of its introduction pathways and taxonomic status.