Background:Numerous methods of age estimation have been proposed. The Demirjian method which was first applied in a French-Canadian population in 1972 is the most frequently used dental age estimation method. However, a constant over estimation using this method has been reported by numerous researchers. The Willems method is a modification of the above and was first applied in a Belgian Caucasian population in 2002. Several studies in the recent years found Willems method to be more accurate than the original Demirjians method.Objectives:The objective of this study was to evaluate the applicability of Willems method for dental age estimation in 6 -15-year-old North Indian children.Methods:The sample for this cross sectional study consisted of 390 OPGs of (215 boys and 175 girls) randomly selected from the patient records of a post graduate training dental college in North India. Exact chronological age of the subjects (in years and months) was calculated. The OPGs were used to score the seven mandibular teeth and dental age was estimated using the tables proposed in Willems method.Results:Significant correlation between the chronological age and dental age estimated using Willems method was observed in both males (r = 0.90) and females (r = 0.87). The mean difference between estimated DA and CA for males was 0.004 ± 1.08 years (P = 0.94). While for females, it was 0.031 ± 1.18 years (P = 0.72). The results showed no statistically significant difference between chronological age and dental age estimated using Willems method in the study population.Conclusion:Willems dental age estimation method without any modification can predict the chronological age of 6-15 year old North Indian children with good accuracy.