A 43-year-old Japanese man had an increasing level of serum CEA pointed out by annual physical check-ups. No abnormal findings were detected in the lungs or gastrointestinal tract. The only pathological lesions were a 1.5-cm-sized nodule in the pancreatic tail and a 5-cm-sized thyroid tumor. The thyroid tumor was shown to be medullary carcinoma by aspiration cytology. He underwent total thyroidectomy with extensive lymph node dissection. After thyroid surgery, the patient received distal pancreatectomy 2 weeks later. Pathological examination revealed the pancreatic tumor to be a metastasis of thyroid medullary carcinoma. The patient is alive and well without recurrence 5 years after thyroidectomy and pancreatectomy. The serum levels of CEA and calcitonin remain within normal limits. Thus, the patient seems to have had a solitary metastatic tumor from thyroid medullary cancer.