We report a case of esophageal metastasis from papillary thyroid cancer diagnosed by I SPECT/CT. A 70-year-old man presented with increasing thyroglobulin levels 13 years after thyroidectomy and ablation with I for thyroid cancer. The whole-body radioiodine scan demonstrated marked tracer uptake in the mediastinum, and SPECT/CT could clearly localize the activity to the esophagus. Subsequent surgical resection with histopathologic evaluation revealed an esophageal metastasis from papillary thyroid cancer. I SPECT/CT is a valuable tool for evaluation and precise anatomical localization of the foci of radionuclide activity in thyroid cancer, enabling adequate treatment.