Local recurrence of differentiated thyroid carcinoma in a 67-year-old woman was treated by topical injection of OK-432 every 2-4 weeks. Recurrent tumors turned into small scar-like tissues after 9 months of OK-432 administration. The bleeding from the tumor was well controlled. Secondary recurrent tumors were also effectively treated in the same manner. About 2 years have passed since the start of the treatment and the local recurrence is well controlled. We conclude that topical injection of OK-432 might be a good modality of treatment for the local recurrence of thyroid carcinoma.