Bisphosphonates are effective therapy for osteoporosis, Paget's disease, and metastatic bone disease. Generally, the side effects of bisphosphonates are minimal. Recently, an uncommon adverse reaction affecting the maxilla or mandible, called osteonecrosis of the jaw, has been reported, especially in those patients receiving high doses of bisphosphonates in the oncology setting. Regarding doses used to treat osteoporosis, clinicians must keep the very small potential absolute risk of jaw osteonecrosis in perspective and consider it in relation to the demonstrated benefit of bisphosphonates. Still, in a very small number of patients taking bisphosphonates, intractable, painful, nonhealing exposed bone may occur following dental extractions or denture irritation.