Ectopic thyroid tissue with thyroid gland in its normal location is an extremely rare phenomenon. We present a case of a 38-year-old woman who was referred to our hospital with symptoms of hypothyroidism. Thyroid hormone measurement revealed clinical hypothyroidism with elevated anti-thyroid antibodies, neck ultrasonography showed a small tissue with the characteristic of Hashimoto thyroiditis, while the scintigraphy demonstrated only a lingual thyroid. Treatment consisted in L-thyroxine replacement to the euthyroid state. We reviewed the literature with respect to the embryological background and the clinical management of such cases.