A number of reports have been published describing the ultrastructure of normal taste buds but few have discussed their pathology, particularly in patients with gustatory abnormalities. We therefore conducted an electron microscopic study of biopsy specimens of glossal circumvallate papillae from patients with dysgeusia. We found depletion of microvilli and dense substance in the taste pores, vacuolation and hyaline degeneration of the taste bud cells and condensation of nuclear material and cytoplasm in cells of indeterminate histological type. In one patient with idiopathic dysgeusia, disruption of subsurface cisternae contiguous with the nerve endings was evident in Type II cells. In another patient, who had undergone radiotherapy, the number of cored vesicles in Type III cells was reduced.