The structure of parenchymal components of rat submandibular glands observed with scanning electron microscopy is presented. The glands were fixed, submerged in liquid nitrogen, cryofractured, dehydrated and critical-point-dried. The fracture surface displayed the acini, granular ducts and striated ducts. Acini exhibit a typical sponge-like pattern of irregular and empty cavities. Granular ducts are lined by bulging cells laden with numerous secretory granules. Their diameter ranged from 0.2 to 3.2 μm, with a mean value of 1.240.4 μm. Measurement of the actual granules was rendered possible by direct observation. Striated ducts exhibited a cribiform pattern near the basal cell region which corresponds to infoldings of the basal cell membran