Bisphosphonate-related osteonecrosis of the jaws (BRONJ) is a newly emerging condition in a long-term administration of mainly intravenous bisphosphonates for the treatment of hypercalcemia associated with malignancy, multiple myeloma, and metastatic breast and prostate cancers. The incidence of BRONJ is not so high, but it is very refractory to ordinary dental treatments, and the bone exposure, a typical symptom, continues for several months. Although many cases of BRONJ have been reported worldwide, the precise pathogenesis remains obscure. Diabetes mellitus (DM) is one of the systemic risk factors contributing in the development of BRONJ. DM is generally associated with microvascular ischemia of the bone, endothelial cell dysfunction, decreased bone turnover and remodeling, resulting in a delayed wound healing and easy to infection. In this issue, the relation of DM as a systemic risk factor with development of BRONJ as well as the incidence, clinical manifestations and prevention and treatment of BRONJ are described.