Medullary thyroid carcinoma constitutes about 5% to 12% of all thyroid malignancies and has a special interest because of its origin from parafollicular cells, frequent association with multiple endocrine neoplasia(MEN), frequent familial occurrence, and production of calcitonin. Histopathologically, the lesions are characterized by sheets of non-follicular cells surrounded by deposits of hyaline amyloid. Recently, authors experienced a case of medullary carcinoma. So we report this case with review of the literatures.