Ameloblastic fibrosarcoma or ameloblastic sarcoma is an extremely rare odontogenic neoplasm. We report a case of an ameloblastic fibrosarcoma arising from thyroid gland in a 44 year-old woman. Following total thyroidectomy, a histopathologic, immunohistologic, and genotypic examination revealed ameloblastic fibrosarcoma. The tumor was composed of odontogenic epithelium, resembling that of ameloblastoma, and a mesenchymal part exhibiting features of fibrosarcoma. To our review, our case represents the first report of ameloblastic fibrosarcoma of the thyroid gland. Ameloblastic fibrosarcoma may arise from thyroid gland.