Neurofibromatosis (NF) type 1, also known as von Recklinghausen's disease, is an autosomal-dominant inherited disorder. Some tumors may develop in these patients, including optic pathway gliomas, astrocytomas, brainstem gliomas, chronic myeloid leukemia, and rhabdomyosarcoma. Patients with neurofibromatosis type 1 show also an increased risk of endocrine tumors, especially pheochromocytomas, whereas thyroid carcinoma is very rare. It is also rare for a neurofibroma to arise in the tissue neighboring the thyroid gland, and mimicking a nonfunctional thyroid nodule. This report presents a case of a neurofibroma adherent to the thyroid gland with thyroid papillary carcinoma in a 26-year-old woman with NF type 1. © 2009 Springer.