The epithelial cells and their ultrastructural features of the Spermatheca of Ctenolepisma longicaudata have been described. In addition to the epithelial cells, both muscle and cuticular cells are also present in this organ. A variety of secretory vesicles and granules having lysosomal enzymes or mucoproteins is elaborated by the epithelial cells which are subsequently conducted to the apical cytoplasm for discharge in the lumen. Microtubules are involved in the direction of flow of secretory products. Besides, the cuticular and muscle cells of his organ of C. longicaudata make the latter exceedingly complicated for sperm storage, conduction and viability. © 1999 Taylor & Francis Group, LLC.