We report an unmarried woman with papillary thyroid cancer. The patient was a 20-year-old woman who had neck tumor. The ultrasonography (US), CT, and aspiration biopsy cytology (ABC) were performed. The diagnosis of the tumor was papillary carcinoma of thyroid. The total thyroidectomy plus lymph nodes dissection (D2a) were performed. Two years after the first operation, we recognized lymph nodes swelling at her right neck. The US guided ABC was performed. The diagnosis was the metastasis of lymph node from thyroid cancer. We performed lymph nodes dissection again. Three years after the first operation, we detected the swelleing of lymph nodes again at her right neck. We performed lymph nodes dissection again. We recommended a therapeutic use of iodine radioisotopes. However, she rejected the therapy because she strongly wanted to be pregnant. Generally speaking, it is difficult to determine the therapeutic use of iodine radioisotopes for unmarried women. After seven years from the first operation, she delivered a baby girl. We plan to use of iodine radioisotopes for adjuvant therapy when she delivers her 2nd baby. This case suggested that a treatment strategy for unmarried thyroid cancer patients should be made thoughtfully with care.