Age determination in children and adolescents of unknown age is often based on the degree of bone development (Greulich and Pile method). However, the variability of development at puberty, extrapolation to other populations and the use of invasive means make the reliability and feasibility of this method uncertain. Using pubertal criteria that are simple to identify and easily applicable to any population, we distributed a sample of Tunisian adolescents aged 11 to 16 years into pubertal stages. A nonlinear model between pubertal stages and chronological age was obtained by weighted line square procedures using quantile-quantile plots. Tunisian adolescents have an advanced onset of puberty of slightly more than 13 months compared to French adolescents. The use of our model allowed us to estimate with good accuracy the age of Tunisian adolescents based on their biological maturation. The mean differences between estimated age and actual age from these values were 0.12 ± 0.66 years. In 60% of the cases, the differences between chronological age and estimated age are between ± 6 months. The procedure followed uses simple pubertal criteria. This allows the development of a model for age attribution easily applicable to any population and thus avoids the drawbacks observed in other methods.