Osteonecrosis of the jaw in association with long-term use of bisphosphonates (BRONJ) is a relatively rare but serious side effect that is difficult to treat. The incidence of BRONJ in patients treated for osteoporosis is low at 0.1%. The incidence in cancer patients treated with high doses of intravenous bisphosphonates is higher, ranging between 3% and 10%. Risk factors for BRONJ are invasive treatments such as tooth extractions, root canal procedures and the placement of dental implants, as well as trauma caused by pressure from poorly fitting dental prostheses. High-risk patients should be examined by a dentist or an oral surgeon and, if necessary, undergo dental treatment prior to treatment with bisphosphonates. All patients taking bisphosphonates should maintain good oral hygiene, receive regular dental examinations and see a dentist if any oral symptoms develop. Physicians who prescribe medication as well as the patient's dentist and oral surgeon should be aware of the use of bisphosphonates and BRONJ as a possible adverse reaction. This requires cooperation and the exchange of information between a patient's health care providers.