Glomerular segmental sclerosis(GSS) can be seen in the context of renal allografts as a manifestation of chronic rejection or recurrent FSGS. We collected 14 cases containing more than 8 glomeruli in histologic sections and showing GSS among 85 renal allograft biopsies and subdivided into 2 group, based on the underlying histology for the clinicopathologic orrelation. They were 13 males and one female, and the mean age was 33 yrs in group I(with normal appearing tubules and interstitium) and 40 yrs in group II(with chronic rejection). The interval between renal allograft and biopsy were 7 and 37 months respectively. All had proteinuria, 0.4 to 23.1 gm/24hrs(rnean; 6 gm), and all of group I and half of group II were in the nephrotic range. The level of proteinuria was higher in cases without tubulointersti tial change than in those with chronic rejection, and did not correspond to the length of posttransplant period. Transplant glomerulopathy was coexisted in two of group II. Cyclosporine associated arteriolopathy was noted 2 cases and seemed to have no relation with GSS. The percentage of glomeruli affected by GSS were 0-22.2% in group I and 4-30% in group II, and their locations were hilar in 1, peripheral in l 1 and mixed in 2. Immunofluorescent examination could be done in 13 cases: negative in 4, IgA in I, IgM in 7 cases in mesangial pattern. Vascular C3 deposition was noted in 7 cases and regarded as nonspecific. We concluded that GSS in posttransplant kidneys indicated profuse proteinuria, especially in cases with normal or near normal tubulointerstitium