Background: Many of dental treatment need location of mental foramen and presence of accessory mental foramen because it is very useful in anaesthetists in nerve block for any surgical procedures. It also prevent nerve from injury Objectives: To determine the shape and orientation of the mental foramen by a visual examination. Material and Methods: The present study was conducted using 100 dried human mandibles of both unknown sexes. Shape and position of mental foramen and accessory mental foramen from tooth number Results: In present study 64 mandibles having round shape and rest 36 are oval in shape. Accessory mental foramen was present in 4 mandibles and was unilateral in position. Conclusion: The knowledge about variation in, shape and position of mental foramen and presence of accessory mental foramen may be helpful to the dental surgeons to achieve full anaesthesia after nerve block.