Isolated asymptomatic brain metastasis in papillary carcinoma thyroid (PCT) is extremely rare. We here present such a case of a 48-year-old woman with PCT. SPECT/CT localized the 131I radiotracer concentration seen on whole-body scan in this patient to the right posterior parietal cortex, suggesting brain metastasis. Contrast-enhanced MRI and 18F-FDG PET/CT confirmed the diagnosis and the patient was taken for gamma-knife radiosurgery. 131I SPECT/CT in this case accurately restaged the patient by detecting asymptomatic isolated brain metastasis and correctly directed the management strategy.