Seventy-five adult human mandibles were radiographed with a paralleling technique to determine the ability to visualize the mental foramen as well as its size and position. The foramen was seen on 75% of the horizontal periapical radiographs examined. When the foramen was not visualized, is was usually below the inferior edge of the film. The radiographic size of the foramen was smaller than the anatomical size previously reported. The position of the mental foramen was usually mesial and below the radiographic apex of the second premolar.