The course of the mental nerve within the mandible was examined in 37 human specimens. Two different types of pathways were found. In 22 cases, a siphon (ie, an arch that travels laterally and cranially) was observed. This type of path was classified as Type I. The distance measured between the mental foramen and the most anterior point of the canal was up to 5 mm. There was no correlation between this distance and the degree of atrophy. In 15 specimens, the mental canal ascended directly from the mandibular canal to the mental foramen without curving forward. This type of course was classified as Type II. The average angle of inclination between the plane through which the mental canal courses and the horizontal plane was 50 degrees. Based on the present data, it is recommended that a safe distance of at least 6 mm anterior to the mental foramen be maintained when performing surgery in the mandibular premolar region. Keywords: implants, mental canal, mental foramen, mental nerve