BACKGROUND: Age estimation is a major concern in Forensic Medicine for its prime importance in legal, socioeconomic and other global issues like bomb explosions, mass migration & mass disasters both in alive or cadavers. Classical methods based on morphological, radiological or histological methods are being used. The precision and reliability of these methods have margin of error of ± 10 years. There is a need for development of a biological tool at molecular level. Amino acid racemization in dentin is found to be a precise model for age estimation with margin of error within ± 3 years. OBJECTIVES: Current study was designed to determine the correlation of coefficient of aspartic acid racemization (KR) with reference to age. Secondary objective of this study was calculation of margin of error between chronological age & calculated age by racemization method. Third objective was calculation of correlation of gender, socioeconomic status & different age categories with KR (Coefficient of racemization). MATERIALS AND METHODS: This study was conducted in dental outpatients‘ clinics at Ziauddin Hospital, Karachi. The duration of study comprised of two years 2011-2013. It was a Cross sectional study and sampling technique was convenient sampling Sample size calculated was 116 subjects. ERC approval was taken. An oral expressed consent of patients was taken. Preliminary data including name, gender, chronological age (Y-M-D), socio-economic status, educational status, monthly income, occupation and any other factors affecting oral health was entered into a specially designed performa for this study. High-Pressure Liquid Chromatography was performed on each sample to quantify the L and D forms of aspartic acid in dentin. RESULTS: Total sample size was 116 subjects, which were divided into two groups – Test group of 85 subjects of known age group and Validation group of 31 subjects whose age were kept unknown to the researcher. 85 teeth samples of known age group (test group) were analyzed and D/L ratio of aspartic acid was estimated by HPLC technique. Regression line was derived from scatter plot graph and least square method was used to calculate the regression equation. The coefficient of racemization (KR) for each tooth was calculated using the formula KR = In [(1+D/L)/ (1- D/L). For checking whether regression equation would correctly predict the age, the proposed formula was applied for validation group of 31 teeth and then difference between actual age and predicted age of 31 samples were calculated. Co-efficient of determination was found to be 0.96, which show that regression equation for estimating age was 96% correct. There was a very strong positive correlation (0.98) observed between actual ages and co-efficient of racemization, which indicates that as age increases co-efficient of racemization increases. CONCLUSION: As the correlation coefficient proved to be strongly positive, it suggests racemization of human dentine could be used as a precise method for estimation of chronological age in living and in dead. The error of margin between calculated and chronological age was ± 2.44 years in 116 subjects. PValue was significant among different age groups. KR coefficient has significant correlation with age rather than gender and socioeconomic status. HPLC is a reliable technique to estimate the coefficient of racemization because it is highly reproducible, cost-effective and convenient. However there is a need for extensive research towards standardization of the method to enable quality assurance within and between laboratories.