Osteoporosis-related fractures (low-trauma, fragility fractures) are associated with significant morbidity, mortality, and health care expenditure worldwide. In the absence of a defining fracture, the diagnosis of osteoporosis is based on the World Health Organization's T-score criteria using central dual-energy x-ray absorptiometry (DXA). Paradoxically, the majority of those patients who will sustain a low-trauma fracture do not meet the T-score definition of osteoporosis. Conversely, younger individuals with bone density in the osteoporotic range but no other risk factors have relatively low fracture rates and yet are frequently considered candidates for osteoporosis therapies. The limited accuracy of bone density testing alone to predict fractures has led to the development of a variety of fracture assessment tools that utilize the combination of bone density and clinical risk factors to improve the prediction of low-trauma fractures. These fracture assessment tools quantitatively predict the 10-year fracture probability of hip and major osteoporosis-related fractures, and can be used to define cost-effective intervention strategies for primary and secondary fracture prevention.