This study was conducted to compare intersexual similarities and to determine the anatomical differences in rat mandible as a result of being in rodents group. Total 20 female and 20 male Wistar Albino rats of 20 weeks age were used. Rats were sacrified under ether anaesthesia and macerated. Mandible were recovered, length and height measurements were determined and evaluated statistically. Measurements of the total length of mandible 2 (TMU2) and the length of the mandibular incissiv corona (MICU) had differences between sexes and the difference was statistically significant (p<0,05).