The International Society for Clinical Densitometry (ISCD) has developed Official Positions to assist healthcare providers in addressing some of the issues inherent with the use of bone mineral density (BMD) assessed by dual-energy X-ray absorptiometry (DXA) to diagnose osteoporosis, apply World Health Organization (WHO) T-score classifications, and monitor BMD changes over time. Differences exist, however, between the ISCD Official Position statement and that of the International Osteoporosis Foundation with respect to WHO criteria for skeletal sites. Consequently, a subcommittee of the ISCD was directed to address the application of the WHO classifications to specific skeletal sites and regions of interest. In 2005, the ISCD Position Development Conference reviewed the findings and prepared Official Positions, which address whether or not: (1) the lowest T-score of the total proximal femur, femoral neck, trochanter, and spine should continue to be used for diagnosis; (2) the WHO classification may be applied to a single vertebral body T-score; and (3) the ISCD should endorse the use of the National Health and Nutrition Examination Survey database for proximal femur T-score derivation. The resulting ISCD Official Positions, with their corresponding rationales and evidence are provided here, as well as questions that will need to be addressed in the future.