OBJECTIVE: Bisphosphonate-related osteonecrosis of the jaws is a rare, but morbid, condition. We present the clinical and imaging features of 19 patients. METHODS: A review of 19 bisphosphonate-related osteonecrosis patients was performed. Patient demographics, diagnosis, dental procedures, symptoms and clinical findings, location and pattern of involvement, and presence of fractures, sequestra, and fistulae were documented. RESULTS: Patients included 14 women and 5 men aged 48 to 80 years. Diagnoses included breast carcinoma (n = 11), multiple myeloma (n = 4), osteoporosis (n = 4), prostate carcinoma (n = 2), and lymphoma (n = 1). Seventeen patients received intravenous and 2 received oral bisphosphonates for 2 to 5 years. Bone involvement was noted in the mandible (74%), maxilla (16%), and both (10%). A lytic and sclerotic pattern was most common (58%). Additional findings included fractures (n = 5), sequestra (n = 4), and oroantral fistulae (n = 2). CONCLUSIONS: Bisphosphonate-related osteonecrosis is a rare, but morbid, condition, and imaging features can mimic other conditions. It is important for the radiologist to consider this entity in the appropriate clinical setting. © 2009 by Lippincott Williams & Wilkins.