Two cases of medullary carcinoma of the thyroid presenting as tumours of the pharynx and larynx are described. One patient had a tonsillar mass that resembled a carotid body tumour clinically, radiologically and microscopically. The other had an arytenoid tumour with multiple cervical lymph node metastases but without intrathyroidal carcinoma. The endocrine nature of the neoplasms was indicated by the presence of stromal amyloid, cellular argyrophilia and secretory granules whilst the demonstration of calcitonin and carcinoembryonic antigen provided evidence that they were medullary carcinomas.