The ultrastructure of the foveal glands of adult Hyalomma dromedarii is described. Sexual dimorphism is evident in the form of the fovea dorsalis, numbers of slitlike pores, and arrangement and numbers of lobes. A regulatory mechanism for opening and closing foveal pore tubes is probably present. The foveal glands are apparently fully formed when the female emerges from the nymphal molt; however, secretory cells lack osmiophilic-neutral lipid droplets and 2,6-dichlorophenol (DCP) sex attractant. Osmiophilic-neutral lipid droplets within vesicles and DCP in the gland are demonstrated in the mature unfed female. Female feeding results in vesicle disruption and secretory droplet release into the cell cytoplasm and ducts. Mating and full engorgement lead to secretory droplet depletion. Secretory cell ultrastructure is similar in the male and female, but in males osmiophilic material is not organized into discrete droplets and DCP is absent. Foveal gland innervation is described.