A 26-year-old man with a history of nasopharyngeal carcinoma (NPC) presented with bone metastasis. Bone scan revealed diffuse skeletal metastases with superscan appearance. Afterward, radiotherapy for bone lesions was arranged and the effects were evaluated. The bone scan flare phenomenon appeared within a short time after radiotherapy. Diffuse bone metastasis, which is common in NPC, were indeterminate on images showing superscan pattern or flare.