The adrenergic innervation of the rat submandibular and parotid glands was investigated by monitoring the uptake of H3-NE by nerve terminals with electron microscopic autoradiographic techniques. Both glands contained nerve bundles in the stroma encompassed by a Schwann cell sheath. Silver grains due to H3-NE were observed overlying several nerve terminals found in these nerve bundles, while other nerve terminals in the same bundle were devoid of silver grains. In the submandibular gland, adrenergic nerve terminals characterized by silver grains due to H3-NE were observed in the stroma in close relationship to, but not in direct apposition to parenchymal cells. In the parotid gland, silver grains due to H3-NE were observed overlying nerve terminals contained within the basement lamina and in close contact with acinar cells.