Many patients with end-stage renal disease have altered host defenses against infectious agents. We have demonstrated that T cells, which play an important role in the immunological response, may undergo apoptosis by the Fas system in uraemia. To elucidate whether gammadelta T cells, which function as a first defense against intracellular pathogens, are altered in number or characteristics in dialysis patients, surface expressions of TCR, LFA-1 and Fas antigen on peripheral T cells were examined by immunofluorescence analysis. We demonstrated that the proportions of peripheral gammadelta T cells are altered significantly in haemodialysis (HD) patients. Interestingly, there were marked differences in the levels of expression of LFA-1 and Fas antigen between the two types of T cells. Moreover, both the expression of LFA-1 and that of Fas antigen were enhanced significantly in HD patients compared with normal controls. These results suggest that circulating gammadelta T cells may be susceptible to activation-induced cell death in comparison with alphabeta T cells in uraemic environments.