Accumulating evidence has shown that the risk of osteoporotic fracture is increased in patients with type 1 and 2 diabetes mellitus. Measurement of bone mineral density is not a good evaluation tool for diabetes-related osteoporosis because the underlying mechanism is based on the deterioration of bone quality with accumulation of collagen cross-links of advanced glycation end products, decreased bone formation, and cortical porosity. Thus, we should choose the anti-osteoporosis drug while taking the mechanism into consideration. However, the evidence of treatments for diabetes-related osteoporosis is not sufficient so far. Therefore, further studies are necessary to solve this issue in future.