The cross sectional, descriptive study was conducted to find the reference data for bone mineral density (BMD) in normal women in the area around Thammasat University Hospital. The study population consisted of 806 women aged 15-80 years. BMD of different parts of the body were measured by dual energy photon absorptiometer. The results showed that mean (+/- SD) BMD of the lumbar spine 2, 3, 4, neck of femur, Ward's triangle of femur, greater trochanter of femur, ultradistal part of radius, and distal ulnar averaged from all age groups were 0.954 +/- 0.144, 1.027 +/- 0.151, 1.059 +/- 0.147, 0.898 +/- 0.114, 0.774 +/- 0.165, 0.777 +/- 0.103, 0.412 +/- 0.073, and 0.585 +/- 0.096 g/cm2 respectively. Overall, the peak BMD was between the age of 40-44 years old. It started decreasing from the age of 45 and decreased remarkably after the age of 50. The data is shown to be a database for our hospital's health policy, but the authors believe that it could also be used as reference data for future studies in Thailand. It is suggested that normal values in different areas should be available in the future in order to provide more specific and better health care according to demographic variation.