Age estimation is one of the prime requisites in forensic human identification cases and the criminal justice system. There are several age estimation methods using dental parameters. A method proposed by Mincer et al. which uses the mineralization stages of third molars based on Demirjian's developmental stages is less tested in the Indian population. The present study aimed to assess the developmental status of the third molars and to apply and validate Mincer et al.'s method on the Western India population. A total of 306 orthopantomograms (OPGs) from 128 males and 178 females with a mean age of 16.89 years ± 3.68 were analysed. Demirjian's A-H staging was applied to record the developmental stages of 1100 third molars. Mincer et al.'s mean age of attainment was applied based on the American Whites (Caucasian) population for males and females separately using stages of #18 and #38. There was a slight overestimation of the chronological age (CA) in both #18 and #38. The females showed more accurate estimated age (EA) than males. Mincer et al.'s method is a convenient age estimation method using the third molar's developmental stage. The mean age of attainment mentioned in the original Mincer et al.'s study can be used in the Western Indian population, with a residual value ranging from 0.21 to 0.25 years.