Objective: To estimate age from mandibular third molar maturation stages in the patient presenting to the Combined Military Hospital, Peshawar Pakistan. Study Design: Cross-sectional. Place and Duration of Study: Department of Dentistry, Combined Military Hospital, Peshawar Pakistan, from Jun to Jul 2021. Methodology: One hundred and fifty participants of either gender, ages 14 to 24 years, with good quality orthopantomogram (OPG) showing mandibular third molar tooth germs and Pakistani nationals were included. Participants with hypodontia, oligodontia, Amelogenesisimperfecta, Dentinogenesisimperfecta, history of trauma /fracture in the third molar region and any systemic disease were excluded. Data like age, gender and tooth maturation stages of right mandibular molars were recorded. Results: The mean age was 16.76±2.19 years. In 111(74.9%) cases, the variation in chronological age can be explained by mandibular third molar maturation stages. The only statistically significant predictor for age was Demirjian's stage of lower third molar (p=0.002,95% CI=3.643-15.442), while gender was not a significant predictor. Conclusion: The age can be estimated from the mandibular third molar with reliability in our population.