A case of basal cell adenoma of the parotid gland is reported. The tumor was studied by electron microscopy, and fine structural features included numerous desmosomes, large secretory granules, and replication of the basal lamina. Myoepithelial cells were not observed. The observations support the view that the tumor is monomorphic and that it arises from serous cells of the acini or intercalated ducts. The tumor may be the benign homolog of the adenoid cystic carcinoma.