Objectives: The study was planned to evaluate the role of morphometric analysis of foramen magnum in determining sexual dimorphism. Also, we have compared the measurement of foramen magnum with age of individual. Material & Methods: study was retrospectively and scans of CBCT were retrieved from archives of department. Length and width of foramen magnum in adults was measured. The data was statistically analyzed. Results: Mean length and width of foramen magnum was greater in males (34.65mm, 31.22mm) as compare to females (33.59mm, 30.11mm) and it was statistically significant (p<0.05). Mean length decreased in dimension i.e. from 35.22mm to 33.73mm as age progressed (18-60 years). Conclusion: Sexual dimorphism can be determined using foramen magnum dimensions. However, age estimation by morphometric analysis of foramen magnum requires more research.