The five-toed jerboas of genus Allactaga Cuvier, 1837 have been distributed in arid and semi-desert regions throughout northern Africa, Iranian Plateau and Central Asia to Mongolia. This genus has 12 species of which five have been so far reported from Iran including, Small Five-toed Jerboa (A. elater), William’s Jerboa (A. williamsi), Euphrate’s Jerboa (A. euphratica); Hotson’s Jerboa (A. hotsoni) and Firouz Jerboa (A. firouzi). The Toussi Jerboa (Allactaga toussi sp. Nov.) is reported for the first time from the steppe regions of north east Iran. This new species is different in external, cranial and molars morphological and morphometric characteristics from its parapatric species i.e. Allactaga elater, and other Iranian five-toed jerboas. Multivariate analyses also confirm that Allactaga toussi sp. nov. is significantly distinct from other species.