The distribution of T6-positive cells in glands from three healthy individuals and 18 patients suffering from various systemic disorders was studied using OKT 6 and NA1/34 monoclonal antibodies in an indirect immunoperoxidase method on frozen sections. Although no positive cells were seen in the glands of healthy controls, 10 of the 18 biopsies from the patient-group contained T6-positive cells which were mostly within glandular epithelium. The presence of T6-positive cells appeared to correlate with lymphoid infiltration of the glands. Only one of the 8 patient biopsies showing normal or minimally-altered structure contained T6-positive cells. Thus these cells are unlikely to play a role in the normal physiological function of labial salivary glands.