OBJECTIVES: To evaluate the correlation between T-score of lumbar spine and that of proximal femur using dual energy x-ray absorptiometry (DXA) and the accuracy of the diagnosis of osteoporosis. MATERIAL AND METHODS: From December 2009 to January 2012, 300 female patients were selected who underwent bone mineral density (BMD) test using DXA. After measuring BMD of proximal femur and lumbar spine, the score of BMD in each age group was compared by two sites. Also, the concordance of the diagnosis of osteoporosis was evaluated. RESULTS: The result showed significantly lower T-score and BMD as it goes to the elderly group. As it goes for 60's age group and even more for 70's age group, lumbar spine showed lower BMD than proximal femur. In all age groups, lumbar spine and proximal femur T-score showed significant correlation; however, it showed the least states at 60's age group. Discordance rate of osteoporosis diagnosis was 33% and 47.3% each at lowest t-score and total t-score. 60's age group showed the highest discordance rate, and osteoporosis group showed the highest rate. CONCLUSIONS: When measuring BMD for diagnosis of osteoporosis, since it shows significant discordance between proximal femur and lumbar spine, it is necessary to measure BMD simultaneously on both parts.