The role played by the ciliated cells of the salpinx in the transport of the ovum has been the subject of numerous studies. In this work we examined the ultrastructure of the cilia of the ampullary portion of the oviductal epithelium in a series of mammals and in man. We found the classical structure of the motile cilia. The free part of the cilia, surrounded by the cell membrane, is composed by nine peripheral doublets and by a pair of central microtubules. In the species we examined, we had the occasion to observe an ultrastructural particularity of the cilia. It is about a group of microcilia placed on their apical extremity. These formations were observed in longitudinal sections and appeared aligned on the top of the cilium. They have a length of 200–300 Å and a diameter of 100 Å. Their number varies with the species examined. The proportion of cilia which presented microcilia is also different from species to species. The functional role of the microcilia is unkn