Cancer patients receiving bisphosphonate therapy, both intravenously and orally, are predisposed to developing osteonecrosis of the jaw. We present a case of a 66-year-old man with metastatic prostate cancer who spontaneously developed avascular necrosis of the mandible after being on intravenous zoledronic acid for 1 year. Jaw osteonecrosis commonly presents with mild to severe jaw pain. Although most of the reported cases give a history of dental procedures, there have been cases of osteonecrosis developing spontaneously. In cases of established osteonecrosis of the jaw, there is little evidence to suggest that the discontinuation of bisphosphonate therapy aides in healing, as bisphosphonates have a very long half-life in the bone tissue. Treatment measures include evaluation by dental and oncological services, consideration for antibiotic therapy, and mainly a minimally to nonsurgical approach. In the absence of a definitive cure, the emphasis rests greatly on prevention.