Pulmonary metastases from a carotid body paraganglioma developed in a patient with von Hippel-Lindau disease. On electron microscopic examination, these metastases consisted solely of chief cells that contained membrane-bound, dense-core granules and formed numerous cytoplasmic processes. These data support the hypothesis that the chief cell is the sole neoplastic cell in paragangliomas. Finally, to our knowledge, this clinical association of a malignant carotid body paraganglioma and pheochromocytoma in von Hippel-Lindau disease is unique.