The mental foramen position changes because of individual characteristics, and the knowledge of its location is paramount in a number of surgical procedures. This study's goal was to assess its position in relation to dentition and its symmetry in a Brazilian population. One hundred ninety-one dried jaws were divided in 3 groups according to the presence or absence of dentition and bone resorption in the foramen region. Standardized measurements of the distance between the foramen and anatomical references were made to establish its position and symmetry. The majority of the specimens studied belonged to white (74%) male (72%) individuals. The foramen most frequent position, using the teeth as reference, was between the premolars for both sexes (males, 41%; females, 60.3%). Most of the mandibles (56%) did not present symmetry between the right and left sides. Accessory foramina were found in 13.6% of jaws. The most frequent position of the mental foramen was between the premolars (position III of Tebo and Telford [Anat Rec 1950;107:61-66]), and they were predominantly asymmetric. The group with no teeth in the mental foramen area showed a reduction of the distance between the alveolar margin of the jaw and the mental foramen.