Background: Bone mineral density (BMD) of the spine and the femoral neck are accurate indicators of the bone mass and thus useful predictors of fracture risk. Dual energy X-ray absorptiometry (DEXA) is the easiest, yet the most precise and non-invasive technique. The need for a population-specific normative BMD data is vital in preventing mislabelling or misdiagnosis of osteopenia or even osteoporosis. Aim: This study was performed to determine the lumbar vertebral and the proximal femur BMD measured by DEXA in 280 normal Iranian men and women. Method: Subjects were selected randomly from different social economic classes in Tehran. Normal subjects were selected for each decade and both sexes. BMD was measured with a Hologic QDR 1000+ densitometer, for the lumbar spine (L1, L2, L3, L4, L1-L4) and the femoral neck (neck, trochanter, intertrochanter, ward triangle, total). Data were treated by polynomial approximation (3rd degree). Results: In women, the highest BMD recorded was 1.020 g/cm2 for the lumbar spine (mean L1-L4) at the age of 31 years, and 0.832 for the femoral neck at the age of 34. In men, the highest BMD recorded was 0.987 g/cm2 for the lumbar spine (mean L1-L4) at the age of 36, and 0.907 for the femoral neck at the age of 30. The highest BMD in spine was lower in men than women. Conclusion: The BMD of both lumbar spine and femoral neck (in both sexes) was lower in this study than the Hologic standards. ©Asia Pacific League of Associations for Rheumatology.