Patients with end-stage renal disease have prematurely aged T cell systems. We tested whether T cell aging parameters were associated with the risk of infections after renal transplantation (RTx). We studied 188 patients over 1 year. Peripheral T cells were analyzed before and at 3 and 6 mo after RTx for frequency of recent thymic emigrants, relative telomere length and differentiation status. These parameters were related to the occurrence of opportunistic and serious infections. Overall, 84 patients developed an infection. In this group, 50 developed an opportunistic infection and 53 developed a serious infection. T cell aging parameters assessed before RTx were not associated with infection risk. The memory T cells showed a decrease within the first 3 mo in both groups (p < 0.001). The CD4(+) memory T cells increased between 3 and 6 mo within the infection group (p = 0.015). The number of CD8(+) memory T cells increased in both groups (p < 0.001) but reached baseline levels only in the infection group. In the infection group, the CD8(+)CD28(null) T cell percentage increased between 3 and 6 mo (p = 0.024), tending to be higher than at baseline (p = 0.061). These differences in post-RTx dynamics resulted from infections. Parameters of uremia-associated premature aging of peripheral T cells do not predict posttransplant infections. Through analysis of T cell differentiation status, the relative telomere length of T cells, and the frequency of recent thymic emigrants, defined as T cell aging parameters, the authors observe no association between the development of infection after renal transplantation and the degree of premature T cell aging prior to transplantation in end-stage renal disease patients.