Little or no genetic divergence is detected using mitochondrial 16S rDNA sequence comparisons across the entire geographic range of the scorpion Euscorpius italicus (Herbst 1800) from Switzerland, Italy, Slovenia, Greece and Turkey. This is consistent with known absence of patterns of allozymes and morphological variation. Euscorpius italicus is found almost exclusively in human habitations. Its sister species, E. naupliensis, exhibits much higher genetic diversity within southern Greece. We suggest that the natural populations of the thermophilic E. italicus underwent a bottleneck during the glaciations, and that its modern range could be a result of dispersal with humans.