Since Albright first proposed the concept of "diabetic osteopenia", many studies have investigated the levels of bone mineral density (BMD) and the risk of osteoporosis in type 1 and type 2 diabetes. The presence of osteoporosis in type 1 diabetes seems to be a reliable evidence. On the other hand, there is still some controversy about the risk of osteoporosis in type 2 diabetes probably due to different pathogenesis, clinical stage and environmental factors. Although details of the pathogenic mechanisms are not fully understood, low insulin secretion, insulin resistance, hyperglycemia, adipocytokines and other diabetic complications including diabetic triopathy may determine changes in diabetic bone metabolism. Recent findings suggest that several drugs for life style-related disease such as statins, beta blockers and thiazolidinediones may have a potential role to promote bone formation other than their own therapeutic effects.