Aim: to assess mental foramen as a landmark for sex determination through morphometric analysis done on digital panoramic images. Methodology: 100 digital panoramic images of dentulous and partially edentulous Egyptian patients (50 males, 50 females) of age over 18 years old were included in this study. Morphometric analysis of mental foramen was conducted on all images concerning one side . Measurements of distances from the superior border of the mental foramen to the alveolar crest of the mandible (D1), from the superior border of the mental foramen to the inferior border of the mandible (D2), from the inferior border of the mental foramen to the inferior border of the mandible (D3), from the mesial border of the mental foramen to the distal border of the mental foramen (D4) and from the superior border of the mental foramen to the inferior border of the mental foramen (D5) were performed on each digital panoramic image. The data obtained were subjected to statistical analysis and discriminant function analysis was used to estimate the efficiency of each variable for sex determination. Results: (D2) and (D3) were significantly higher in males than in females and they showed the greatest contribution as predictors for sex determination. The cutting score was zero, therefore, discriminant scores greater than zero were classified as male and less than zero were classified as female. Accordingly, 70 % of the cases of the cross-validated group were classified correctly. Conclusion: (D2) and (D3) exhibit sexual dimorphism and can be used in sex determination.