Abstract: In the present investigation position of mandibular foramen of the mandible in relation to other landmarks were studied. Panoramic x-ray of 103 females and 94 males who come to above mentioned clinic selected by available sampling. All samples were Iranian with the age above 18 years old. X-ray machine and method were same for all samples. Special landmarks in right side of mandible were identified and their distance from mandibular foramen were recorded by millimetric ruler. The measured landmarks were as follow: Mandibular angle, Coronoid process, Mandibular notch, Head of mandible, Posterior border of ramus of mandible, Anterior border of the ramus, External oblique line, Mylohyoid line, Occlusal plane: mandibular angle were measured by protractor. Results between male and female were compared by Mann whitney U test. The average of both sexes ages were 34.7 years. Difference between distance of mandibular foramen from following landmarks between male and females were significant: (1) Mandibular angle, (2) Head of mandible, (3) Posterior border of ramus, (4) Mylohyoid and (5) Occlusal plane. Present investigation revealed position variation of M.F. in relation to other landmarks and differences between male and female, we suggest kind of investigation individual under 18 years old.