Background and Objective:Given the growing awareness about the important role of children’s age in building bone for a person’s life, physicians need to assess bone health in high-risk children for bone density disorders more than before to optimize their bones’ density and prevent osteoporosis in future. The aim of this study was to evaluate bone density based on chronological and bone age.Materials and Methods:In this cross-sectional study, 80 Patients who have been referred for bone density to the Osteoporosis Centre of the Children’s Medical Centre over a one-year period (spring 98 to spring 99) were studied. Bone density was performed for all patients by using DEXA method.Results:The z-score mean chronological age for the lumbar spine was −0.8± 1.85 years and bone age was −0.58±1.64 years. The z-score mean chronological age for femoral bone was −1.6±1.02 years and bone age was −1.32± 1.4 years.Conclusion:Results showed that in all patients, the difference in the mean Z score of chronological age and bone age of the spine between patients was not significant but for femur was significant. Also, use of corticosteroids leads to significant difference between the two age groups’ z-score in femur and spine.