Reliable delimitation of venomous scorpions is not only consequential to toxicological studies but also instructive to conservation and exploration of these important medical resources. In the present study, we delimited species boundary for the the Przewalski’s scorpion from arid northwest China through a combined approach employing phylogenetic analysis, ecological niche modeling and morphological comparison. Our results indicate that the Przewalski’s scorpion represent an independent taxonomic unit and should be recognized as full species rank, Mesobuthus przewalskii stat. nov. This species and the Chinese scorpion M. martensii represent the eastern members of the M. caucasicus species group which manifests a trans-Central Asia distribution across the Tianshan Mountains range. We also discussed the likely geographic barrier and climatic boundary that demarcate distributional range of the the Przewalski’s scorpion.