The seminal vesicle epithelium of the mouse and golden hamster was examined by light microscopy and by transmission and scanning electron microscopy. By transmission electron microscopy, in the seminal vesicle epithelium of both animals secretory epithelial cells which consisted of mostly light and a few dark cells were observed. The epithelial cells possessed secretory granules which contained a densely stained core. The secretory granules in the mouse epithelium reacted weakly with periodic acid-Schiff (PAS) stain and were slightly stained with alcian blue (AB), and those in the golden hamster exhibited strongly positive reactions with PAS and AB. The nuclei in the mouse tissue were spherical or ovoid, and those in the golden hamster tissue had a few lobes. By scanning electron microscopy, the apical surfaces of most of the epithelial cells were commonly flat or domed, and those of some epithelial cells protruded into the lumen as apocrine-like processes, or possessed small and large orifices. Besides the epithelial cells, there were cells characterized by pseudopodium-like cytoplasmic projections, a few membranous structures, an irregular nucleus, and cytoplasm containing a few dense bodies, in the basal portions of the epithelial cells, or between the basal lamina and the epithelial cells. These cells of the two species were similar in their features.