Breast cancer, prostate cancer, kidney cancer, multiple myeloma, osteoporosis, and the use of antiresorptive and antiangiogenic drugs are risk factors for osteonecrosis of the jaw (ONJ). Denosumab is a Receptor activator of nuclear factor kappa-Β ligand antagonist monoclonal antibody that inhibits the differentiation and function of osteoclasts over osteoblasts. It is an antiresorptive drug used to reduce the development of skeletal events in solid cancers. Denosumab-induced ONJ is a rare condition, occurring in 0% to 4.6% of cases. In this case, the findings of 68Ga prostate specific membrane antigen (PSMA) positron emission tomography (PET)/Computed Tomography (CT) and 18F Fluorodeoxyglucose (FDG) PET/CT are presented in a man with metastatic castration-resistant prostate cancer who developed ONJ due to denosumab use.