BACKGROUND: Persian fallow deer (PFD), Dama dama mesopotamica, is one of the rarest members of the Cervidae family currently listed as endangered by the International Union for Conservation of Nature. OBJECTIVES: Morphological variations in the skulls of male and female PFDs were evaluated in this investigation. METHODS: In cooperation with the Department of Environment, skulls and mandibles were obtained from five male and four female animals. After the usual practices of bone cleaning, the specimens were evaluated for morphological differences. Next, 29 parameters were measured on the skulls and mandibles by a digital Vernier caliper for morphometric studies. In addition, ten, six, and nine landmark points were defined on the left lateral photos of mandibles, dorsal, and left lateral photos of skulls, respectively. The points were digitized on two-dimensional images using the TpsDig2 software. The shape differ-ences between the two genders were analyzed using discriminate function analysis in the MorphoJ software. RESULTS: The interfrontal ridge was more prominent in male PFDs than in female animals. Moreover, there were some significant differences in the measured parameters, mostly in the mandible. The geometric morphometric evaluations showed no significant differences between the two genders. CONCLUSIONS: The findings of the present investigation revealed some morphological differences between the skulls of male and female PFDs